hough these formule do not involve any deration of the length of struts, yet it should 8 be remembered that each strut acts as a , and that the longer it is the greater will liability to spring or bend, hence it is dele always to keep the struts as short as pos; and the form of roof with which we have in the present paper possesses the quality ving short struts in a very marked degree, nay, therefore, be regarded as a very good ral type; and, moreover, there is actually metal required for the construction of such f than for those designed on the basis of the ary upright truss, the saving being in some nces very considerable. In appearance also averted truss principal will bear comparison the upright truss principal.

the construction of trussed roofs of any detion some provision should always be made ightening up the ties, either by contracting - virtual lengths or by increasing that of the against which they react; it appears to us the former plan is preferable.

all descriptions of roof work, it is necessary great care be taken in marking and punching rivet-holes, as in the narrow bars which lly are involved in such structures the resistto stress may materially, if not dangerously, iminished by errors of workmanship. our next article upon roofs we shall proceed demonstrate mathematically the basis and racy of the theory upon which are founded various formulæ given above.

We have received the following from a corDondent:-In your article, "Plate Girders, 2," the writer recommends the top and com booms to be made in the proportion of 1 20. Mr. Fairbairn's carefully made experiats show that the strongest form of section ires the ratio to be at least as 1 to 1-75. If 1 to 1-27 has been derived from more recent ls, I shall feel obliged if some information he given respecting them, as they would icate, I think, a general change in the lity of the metal used or the adoption of a Ferent process of manufacture.

same. To construct this elbow a piece of sheet
metal of the desired length and width is bent in
the form of a cylinder, the lapping edges are con-
nected together at each end by rivets a a; it is
then placed upon a former, by means of which
the metal upon one side of the cylindrical pipe is
caused to buckle outwardly, forming the ribs or
corrugations A upon the surface of least curva-
ture. These corrugations extend radially over
one-half or two-thirds of the curved section of
the elbow. The surface B, of greatest curvature
of the elbow, is smooth. The ends C, C1, are
devoid of corrugations, and enter or receive the
straight lengths of pipe, which, being at an angle
with each other, are connected together by the
elbow.

The usual manner of constructing elbows is to
crimp together short segments of cylindrical pipe,
according to the inventor a tedious and lengthy
operation when compared with the manner of
forming the elbow from one piece of sheet metal
as here described.

IN June, 1858, Sir Charles Wheatstone obtained
a patent for" Improvements in Electric Tele-
graphs and Apparatus connected therewith." This
invention was stated to be "A new combination
of mechanism for the purpose of transmitting
through a telegraphic circuit messages previously
prepared, and causing them to be recorded or
printed at a distant station." This system con-
sisted of three distinct parts.

1st. Of an instrument for perforating the slips of
paper with the apertures required in the order to
form the message.

which last only during its upward or downward motion; (5) a manipulating key, by which alternately inverted currents of equal duration are translever is moved; (6) an arrangement for adjusting mitted independentlyof the speed with which the the printing magnet when oscillating between poles of different magnetic intensities.

In the form of transmitter described in 1858, the rotation of a handle actuates the mechanism which gives motion to the paper strip, and makes the confacts according to the perforations on the paper, and has also like it a rocking piece with a groove to receive the paper strip, a spring clip which holds the paper firmly during the recession of the rocking to the paper strip, which by entering the external piece, and three wires or pins placed transversely apertures thereof, or by being prevented from entering the paper by the absence of apertures, regulate the succession, frequency, and direction of the electric currents sent into the telegraphic circuit.

a

In the form of improved transmitter described in 1867, "instead of having a simultaneous vertical motion, the two exterior pins are elevated alternately, one, being allowed to rock with the middle pin, the other having only a vertical motion."

In the instrument which forms the present improvement the paper strip instead of having an intermittent motion transmitted to it, is drawn forwards by a continuous motion. This is accomplished by spur wheel in connection with the mechanism of the transmitter, the teeth upon the periphery of which enter the central row of holes of the paper strip and draw it through. By this means the central pin and rocking piece are dispensed with. The number of vertical wires or pins are reduced to two, which are connected by a system of suitable levers with the commntating arrangement for inverting the galvanic currents.

A front elevation of the improved transmitter is shown in Fig. 1. The perforated paper strip is drawn with a uniform velocity between the fluted 2ndly. Of an apparatus called the transmitter, roller C and the circular depression in the horizontal the object of which was to receive the slips of ledge B by the spur wheel M, the teeth of which paper prepared by the perforator and to transmit enter into the central line of holes and hold it in the currents produced by a voltaic battery or other position. The vertical wires or pins p, pl, which rheomotor in the order and direction corresponding enter respectively into the upper and lower line of to holes perforated in the slip. The perforated perforations of the paper strip are connected with slip acted upon this transmitter in a manner similar the bell-crank levers I and J, and are forced upto that of the cards of a jacquard loom, allowing wards by the spiral springs s and s. These levers pins to enter the apertures as they present them- are placed on opposite sides of the rocking beam selves or remain depressed when the blank inter- L, and are alternately depressed by the arms 1 and vals pass over them, one row of apertures acting c, which protrude from it at equal distances from upon the pin the depression of which determines its centre. When a hole occurs in the paper strip, the current in one direction, and another row upon through which either of the vertical pins is free to the pin whose depression determines the produc-enter, the lever attached to it follows the beam uption of the opposite current.

3rdly. Of a recording or printing apparatus constructed in such manner as to print dots forming what is called the Steinheil alphabet.

wards, remaining in contact with the arm of the beam on that side, and the circuit remains unbroken; but if no hole occur in the paper strip the vertical pin rising against it is stopped, and the In another patent, Sir Charles Wheatstone de- bell-crank lever prevented following the beam upscribed a modification of the transmitter of the pre-wards. The protruding arm of the beam therefore ceding telegraphic system, the object of which was separates from the lever, and the circuit is interto enable the transmitter by means of the perforated rupted. When either of the vertical wires or pins slips of paper therein described to act upon the rises up through a hole in the paper it engages with receiving instrument of a Morse's telegraph in such one of the grooves of the fluted roller C, which manner as to impress on bands of paper in any re- carries it forwards until the opposite oscillation of quired order the succession of long and short the beam causes it to be withdrawn. The two bellmarks in the same line which constitute the alpha- crank levers I and J are connected together elecbet of that telegraph, instead of the double row of trically through the brass sides of the clockwork; dots required in the former system. The printed the brass spiral springs 8 and s1 tend to press those lines were determined by currents always in the levers into contact with the pins and c of the same direction, and the blank intervals corre- rocking beam. The arm 7 is in permanent connecsponded with cessations of the current. tion with the line. The rocking beam on its righthand side is furnished with a third projecting cone tact arm e in permanent connection with the earth and which with the arm c on the same side of the contre makes (when the beam oscillates) alternate contact with the opposite faces of the two contact levers G and H. The lever H is in permanent connection through the slab F with the copper pole; the lever G is in permanent connection through the slab E with the zinc pole of the battery. When the right-hand side of the beam is elevated the contact arm e presses against the face of G and puts the zinc pole to earth, at the same time the arm c is pressed against H, which forms the metallic prolongation of the copper pole. If an aperture occur in the paper strip at this moment the ends of I and J are in contact with e and 1, and the copper current passes from H through c, I, the springs s and s1, J tol, and line. If on the other hand no aperture occurs in the paper strip, the end of I is prevented following the beam, and the line circuit is interrupted on that side by the separation of the contact c. When the beam is in the opposite position a similar action takes place, with the difference that the other pole of the battery is then put to earth through e, and that the interruption of the line circuit takes place between I and J in the event of no aperture occuring in the paper strip.

In a more recent patent, he described various improvements on the three parts of his telegraphic system which removed many of the former inconveniences and greatly increased its efficiency. The perforator was so constructed that all the perforations required to determine the direction of the currents, and the length of the marks and intervals were simultaneously made by a single touch. The transmitter while preserving the essential principle analogous to the jacquard loom, which constitutes the chief originality of his invention, was so constructed that only one half of the length of the paper band formerly necessary was required, and the currents in one direction corresponded with the marks, and those in the opposite direction with the blank intervals. The printing portion of the receiving instrument was constructed so that while marking lines no more force was required than that necessary to move the extremely light printing roller, all friction usually employed to supply ink to this roller or to press the paper against the inker being avoided.

Since the date of the patent just mentioned, Sir C. Wheatstone and Mr. Stroh have introduced various practical improvements designed to increase the efficiency of the system, viz. (1) an improved transmitter; (2) a method of constructing a relay or translator, acting by alternately inverted instantaneous currents, so that the retransmission of the despatches may be effected under the same circumstances as in the original transmission; (3) a new arrangement of mechanism, by means of which the manual working of one or more perforators may be facilitated without having recourse to hydraulic power; (4) a key to be worked by the hand for transmitting alternately inverted currents,

The arrangement for sending a weak current into. the line at the end of a dash or space is effected by the automatic insertion of an artificial resistance into the battery and line circuit. This is done by means of the contact lever K centered upon a slab K1 between E and F, which is in permanent connection with a resistance coil, and thence with the line. The contact lever K is moved from side to side against screw points upon E and F by the rods

oscillating system is carried upon a vertical arbor, upon the lower part of which the quadrant (Q) of a spur wheel engages with a pinion P, the shaft of which carries a fly above it. Half-way up is a block of ebonite I, carrying a small triangular metal slab H in connection with the blade L of the key, through the spiral wire and screw L. At the top of the oscillating arbor is a small cross with two contact screws G, G1, both of which are to earth through the arbor and frame. The slab H is provided with a vertical pin, which, when the system oscillates, rubs against the face of a spring all which is connected electrically with the line terminal of the key. The line circuit between the blade L and the line terminal is therefore made and interrupted between the pin on H and the spring s11. When the key is at rest the rod K1 draws the arm J forwards, and keeps the left-hand spring s pressed gainst the pin upon the quadrant Q; the oscilating system is therefore held at rest, as is shown in he drawing, the line spring all being pressed from ontact with the pin upon H by the front contact crew G, and the line is therefore to earth. When he knob D of the key is depressed, the blades E nd L being raised to the upper anvils C and Z, the irection of the current is reversed. At the same me the rod K1 is thrust back, causing the rightand spring 81 to press against the pin upon the uadrant Q and make the system rotate as fast as e fly will allow it to. In rotating, the screw G arth) leaves the spring s11, which falls for an inant upon the pin upon H, thereby completing the ne circuit with L2 and L and allowing a current pass into the line. This is however immediately terwards interrupted again by the further screw , which as it comes round forces the spring 11 om the contact pin. When the key is released ain the rod K1 pulls the spring s against the pin the oscillating system, causing the quadrant and to rotate in the opposite direction, and the curat (inverted by the blades L and E) to be transtted in the opposite direction for an instant as 3 contact pin of H passes by the spring 811. When key is not in use for transmitting signals it is ced in its position for receiving. For this pur se the metal block B carrying the bearings of the er K is made turnable about a vertical pin. When eiving, therefore, the knob of the lever is drawn vards the left by which the blade L is brought to t upon a stud R connected with the receiving inument. The horizontal movement of the lever o has the effect of relieving the tension of both springs s, sl, of the interruptor, so as to allow oscillating system to assume a central position I the pin upon H to rest in contact with the line ing 811 Currents therefore arriving at the sta1 pass from the line terminal over all, pin on H, spiral wire L1, blade L, and stud R to the reving instrument.

to give a pipe of 44in. diameter in order that a
velocity of 3ft. per second may be maintained.
3, l = 1, and

Here v =

Therefore h

с 1

S

1.125

1

=

0001 x 3 x 3 x

1-125

water flowing in it is known by experiment to be
approximately proportional to the square of the
velocity, and to the surface of contact. This re-
sistance is called hydraulic friction, and is at once
seen to be very different to the friction of solids on
each other, which is, as we have seen, independent
of the velocity and surface of contact. The friction
of moving water is, moreover, not so dependent on
Or h='08ft. or lin. per foot nearly.
the nature of the surface over which it flows, as It is to be observed that, in consequence of the
if it were a solid, provided that the surface be existence of friction among the particles of running
tolerably smooth: this is owing to the fact that water, the velocity will vary at different parts of
after the friction of the film in contact with the sur- the cross section of the channel; that lamina in
face of the channel is overcome, the only friction contact with the wetted perimeter will be most re-
that remains is that of the fluid particles themselves tarded, and it again will retard that above it, and so
sliding over each other, which will, of course, other on, each in turn retarding that above it less than it
things being equal, always be the same.
itself is retarded by the one below. The maximum
We also see that, as the friction is a function velocity will therefore be found in the centre line of
of the velocity, the velocity of water flowing in a the surface of the channel; but if we wish to deter-
channel of uniform cross section and inclination mine the discharge by experiment we must find the
must ultimately become uniform when the accele-mean velocity, or that velocity which multiplied by
rating becomes equal to the retarding force, pre- the area of the cross section of the channel will
cisely as we saw is the case with a railway train, give the actual discharge from the surface velocity,
owing to the resistance of the air, &c.
which can be measured by means of a float or
otherwise. The following empiric formulæ have
been given for the mean velocity in terms of that
at the surface. Let V be the surface, and v the
mean velocities respectively in inches per second,
then v=V-V+; this mean velocity is the
arithmetic mean between the surface and bottom
velocities, therefore the latter is given by the equa-

Let us suppose then that the velocity of water flowing in channel or pipe of constant section and inclination has become uniform, and let us consider a portion of the channel whose length is 7; let C be the length of the boundary of the cross section of the water less the breadth of the surface (if any); then C is called the "wetted perimeter;" C is therefore the surface exposed to the resistance of the channel. Letv be the velocity of the water in feet per second, h the fall in the distance 1, S the area of the cross section, and Q the discharge in cubic feet per second; then, since the velocity has become uniform, the work done by the water in flowing along the length must equal that expended on the resistances for the same distance.

But the work done by the water in one second is equal to Qh x 625 v Sh x 62.5 foot-pounds, since there are 62.5lb. of water in one cubic foot; and since, by the above laws of fluid friction, the work expended in one second on the resistances is equal to K v2 1 C v, we must have

may be represented by. where is a
quantity analogous to for the friction of solids;
S
the quantity, or the cross section divided by the
wetted perimeter, is called the "hydraulic mean
depth."

The quantity, or the coefficient of fluid friction
is not constant, but varies slightly with the
velocity; thus its value for iron pipes, as given by
Weisbach, is

.000056 + μs =

*000067

In a good many books on hydraulics a mean value of is given, on the assumption that is constant at different velocities; this value is μ = 0001. Thus, substituting this value in the above equation for v2, we shall have

v = 1100

The sixth improvement consists in an adjustment
he printing magnet. When the wire coils upon
two sides of the electro-magnet act with differ-
moments upon the curved permanent steel
gnets which oscillate between them, we eliminate
difference by introducing the tension of a spiral
ng on one side or the other of the zero position.
arrangement for effecting this is shown in Fig.
The axis of the printing magnet A, A, is pro-
ed with an arm b from which a spiral spring c
tretched to a small fusee chain d, d, passing
suitable pulleys and round a small drum with
icrometer screw and graduated dial. When the
-ometer screw is turned so as to cause the fusee such as the following:-A pipe 4in. in diameter,
This value for μ was ascertained by experiments
n to bring the lower end of the spring c in a whose length is 14637ft., and total fall 51.5ft. was
parallel with the axis of the printing magnet found by actual measurement to discharge 11-968
ension is put upon the latter, whilst by turning cubic feet per minute. Here the velocity in feet
either side a bias is given to the deflection per minute must be equal to the discharge in cubic
that side of the neutral position of the mag-feet per minute divided by the area of the pipe in
and the inequality in the moments of the
11.968
ro-magnet coils is thus balanced.
square feet, that is to
109 nearly; hence
∙11
v, or the velocity in feet per second, must be equal
1-81ft. per second; hence we have the

since C, or the wetted perimeter, is equal to the length in feet of a circle 44in. in diameter, thereforeμ = '0001 very nearly. Let now be of the form a + at water flowing in a river bed is subject to ,which is that generally assumed for retarding force is manifest by observing the ity of the water in any of our rivers. Take rivers, and, according to some authorities for ase of a river having a descent of 100ft. from pipes also, and we shall have urce to its mouth, it would enter the sea with ocity equal to that acquired by a body falling in vacuum through 100ft., that is to - 32 X 100 = 80ft. per second, or over 54 an hour, did no retarding force exist. This be about the velocity of the Thames on ng the sea if it met with no resistance on road. The work expended in overcoming sistances on the road is equal to the geological done by the water, such as grinding the rocks, nto sand and mud, and transporting them to

To conclude the subject of friction of water in pipes, &c., let us consider the following example:The diameter of the plunger of a single-acting feed pump is 3in., and its stroke is 3in., it makes 160 strokes per minute, and forces the water into the boiler against a pressure of 50lb. per square inch, through a pipe 10ft. long and 14in. internal diameter; it is required to find the pressure within the pump, supposing the delivery pipe to be straight.

If we suppose that, the pump loses 2-5ths of its theoretical effect we have the actual discharge 160 x 7068 x 35 x 6 = 2375 cubic inches, or 137 cubic feet per minute; therefore, the velocity of the water in the pipe must be 1.37 x 144 1-767

1.7 x 17 x 10 × 4_ 115.6·092ft. 10000 x 125 This head of 092ft. will represent a pressure of water equal to 041b. per square inch nearly, which will be the pressure in the pump over and above the steam pressure necessary to overcome the friction of the pipe. This very small pressure is accounted for by the velocity being so very small, and there being no bends in the pipe; were there four bends of say 3in. radius, the loss of head from this cause would be about 021b. per square inch, this depending also upon the square of the velocity.

RESISTANCE TO THE MOTION OF VESSELS.-This resistance may be divided into two portions, viz., that due to the displacement of the water, and that of the friction of the water against the sides and bottom of the vessel. Each of these resistances is found to vary approximately as the square of the velocity, and therefore the total resistance varies in the same manner. The resistance due to the displacement of the water is caused by the act of separating the water at the bow, and of moving it laterally on each side, through a distance equal to half the breadth of the ship. Let us suppose two vessels, of which the breadth and depth are the same, but of which the length of one is double the length of the other, and which are otherwise of the same shape; in other words, let us suppose two vessels, of which the frames are exactly the same shape, but spaced half the distance apart in one that they are in the other, then it is evident if

both vessels draw the same depth of water and have the same speed, that the same quantity of water will be moved aside by each vessel and that the long vessel will move it aside with but half the velocity that the short one will; thus, in the case of a long vessel, the velocity of the water will be very small in comparison with that of the vessel, and therefore the resistance from this cause will be greater in the case of a short than of a long vessel. On the other hand, the friction of the water, as is the case with pipes and channels, varies with the nature and extent of the surface, so that the resist ance from this cause will be greater for a long than for a short ship. It has been discovered by experiment that this frictional resistance is the chief resistance to the motion of a ship, for vessels have been built to lines which by theory cause the minimum resistance to displacement, and on trial were found to move through the water with little or no disturbance, yet their performances were found to excel but little those of other vessels of the same class of good average lines. Now, if the resistance from cleaving the water was considerable, the vessel built to lines found by theory to be the best for that purpose would have shown a manifest superiority over the others, and as this was not the case the conclusion is that the friction of the bottom and sides is the chief resistance to the motion of vessels through the water.

SELECTED ARTICLES.

ON FERMENTATION.* (Continued from page 584.)

WE had occasion, last week, to notice the effect of the atmosphere on processes of fermentation in several instances. I mentioned, among other things bearing on that question, an experiment of Gay-Lussac, in which he squeezed some very ripe berries of the grape under mercury, and kept them, with due precautions for the exclusion, as far as he knew, of everything except the grape. juice; he kept this expressed juice for some time quiescent, and then introduced a bubble of air, or a bubble of oxygen, the active substance of air, but he subjected the air or the oxygen, before introducing it into this juice, to various strong influences, which must have destroyed any vital organisms in it; and he found that the mere addition of the air to the quiescent juice caused a process of fermenta tion to commence, and a formation of organisms to begin, that they developed themselves, and that the liquid fermented in the usual way. The fact of the fermentation commencing is, if we bear in mind the general results of M. Pasteur's researches, to be attributed to the presence in the mercury or in the grape juice, or somewhere or other in the substances present, of bodies which, by the mere access of oxygen, were stimulated so as to develop themselves into these little vital cells. It is now known, I may say, that there are in mercury, unless it is purified with extraordinary precautions, always present some such organisms, capable of developing themselves under such influences; and it is probable, I will not say more than that, for I do not know, that in the grape-juice there may also be similar germs present. The functions of oxygen appear from that experiment-which has since been confirmed by other observers-to be essential, at all events, to the initiation of the process, and there is in that respect, a remarkable analogy, which I think is interesting to recall to mind, with the action of oxygen on other bodies, as shown by an experiment made by Humboldt many years ago. He got some grains of wheat from Egyptian mummies, which had been so long at rest that they were not inclined to grow, in fact, they could not be got to grow in the ordinary way. However, he stimulated them to activity by immersing them in a little chlorine water. It is well known to chemists that chlorine in the presence of water does oxidise, or cause the oxygen to separate and pass over to common organic substances capable of combining with it. Humboldt actually stimulated these sleepy wheat grains to life, so that they grew and germi nated, and their descendants are still in existence, by the mere action of oxygen developed in that In the processes of wine-making and wine-keeping, the presence of air is one of the most important matters which have to be considered, and there has prevailed, and I ought to say there still prevails, to a certain extent, a difference of opinion regarding the functions of oxygen in these processes. On the one hand, it is known, as a matter of fact, that processes of fermentation are performed under

way.

the access of air to the substance; while other
wine-makers think, on the contrary, that in the
first process as little air should be present as pos-
sible; but there has always been some. The juice
first expressed from the grapes has always been
very carefully examined with regard to the
gases contained in it. If air has access to it, it is
always necessary to know, in order to judge
whether the air acts upon it, whether the air is
dissolved by it, and whether, if dissolved by it, it
is still to be found in the grape juice as such, or
whether it has undergone combination. Now,
every case of the examination of must, or fresh
grape juice, which is not fermented, has shown that
it contains a considerable quantity of gas, but no
case has been established of free oxygen being pre-
sent in it. Carbonic acid gas is present in it in a
considerable quantity, and also nitrogen, in proof
that air had had access to it, but the oxygen which
was taken up at the same time with the nitrogen
from the air, was not to be got out from that must
again. It had been taken up, and it had entered
into combination with the substance, so that all the
oxygen present was actually combined chemically
with it. In that respect a good many observations
have been made by various chemists, but I ought
especially to quote those of M. Pasteur which are
exceedingly careful and valuable. He has shown
that this substance not only eats oxygen, but digests
it. The oxygen is not to be found in it as such,
It is only present in the form of a compound, which
is formed by its action on the organic matters there
present. Then, when the wine juice has been ex-
pressed, and when it has been allowed to remain
some time in a suitable place, so as to undergo fer-
mentation, with a considerable variety of treat-
ment in different places with regard to air, for in
some places it is thought desirable that the fermen-

1

roborates that in a very remarkable va
body knows the difference there is be
and old wine, and the changes which
when the wine is being kept constit
one of the most important parts of the
ject of wine-making. Wine, when its he
has been completed, is found to se
considerable rapidity and avidity, and ra
vours are made to get out from this w
air which has been dissolved in it, it
some kinds of wine allow it to go, or p
again, whilst other wines do not; and a
spect, a distinctive test is found betwe
ties of the wine; for by observing this
the facility with which they give p
they have dissolved, and by comp
the qualities of wines in each case, i **
generalisation has been arrived at. h
I speak upon the authority of others, fa
confirmed it by my own observations à
I do know fully corroborates it. TEA
that whereas low class wines, which p
pay much for, give up again almost
air which they have dissolved, supe
wine do not give up again, they
nitrogen, and hold the oxygen fast i
which is dissolved in both cases, is belt.
is digested by the high class wines; b
digested, but simply eaten by low das ten y
servations have been made in this en
great many observers, especially b
Pasteur, to whom we owe most deras
this respect.

In the process of making wine, there ar siderable number of operations sionally considered rather extrate wine-making, and are by many pass amongst frauds. Materials are sa

tation should be allowed to take place in open aid of the natural constituents of the
vessels, or in vessels to which the air can have ac- materials which contribute to the que
cess as freely as possible, whereas in other cases product; some of them by adding
special care is taken to cover as completely as pos- but others simply removing from the
sible the vessels in which the fermentation is taking bodies which are not wanted in it. Ad
place, so that the air may have as little access as that it does appear to me a great era to
possible to the fermenting substance-and I believe the introduction of any new condities
it is impossibie to give any one general rule with be found to effect an improvement in r
regard to the best process for all cases of fermenta- I do not think it is reasonable to
tion, because the materials which are subjected to cause wine is only known by the valger
fermentation vary so considerably. They differ from grape-juice, that for that reason notang
one another in their composition so materially, and juice ought ever to be used in the mate
there are also other circumstances which are differ. think it would be desirable, in fact, it
ent. For instance, the temperature, which has an almost compulsory, that persons shonlis
important influence. Not only is the temperature materials are present in substances wh
in some localities higher than in others, but other to the public; but, I think, with that sals
circumstances are also different, and it would not would be right to leave manufacturers per
be right to say, because air is found to be perfectly to employ whatever materials they migh
useless in some well established cases during fer- conducive to the elaboration of their pra
mentation, that, for that reason, it ought to be ex- some countries, grape-juice is exced
cluded, or even that it may be excluded, in all other acid and poor in sugar (and I think a f
cases of apparently similar fermentation. As far wine is rather of that class), and wise
as a general rule can be laid down from present such districts find that their stuff is mar
experience, I think it does appear certain that if some of the acid present in it can be
oxygen plays no part in the process after the first fore it is sent out. They, therefore, p
expression of the juice. Once the fermentation has must, in fermenting the wine, some c
commenced, it appears to go on as well if air is ex lime which is present in the chalk c
cluded from the substance as if air has access to it. the tartaric acid, and takes it out of (24
There is, however, one circumstance which is con- Thus, the sour liquor is rendered lase
sidered by persons of considerable experience to be certainly that is not in any degree, or to
important in this matter, and which I ought there- whatever, a fraudulent admixture. Ma
fore to mention, viz., that when fermentation takes added, but only an unpleasant substa
place at a low temperature-and some fermentations from it. It also happens in precisely the
are, with great care, kept at a low temperature-the tricts, that from the paucity of sugar
products are found to be superior if the whole pro- sent in the grape-juice, the wine is
cess is carried on, the temperature being kept ex- alcohol; and that to meet the require
ceedingly low, and in those cases it appears that an sumers, many wine-makers now add
open vessel is certainly not in any degree detri- process. Now, sugar is one of the
mental. It is customary, in fact, to use an open proper constituents of grape-juice, and i
tub when the temperature is low; and, on the con- contain too little of it, it does seem qu
trary, it is usual to use a partially closed vessel, of and desirable that more should be a
course allowing for the escape of carbonic acid, ever, in the subsequent making of wi
when the temperature is comparatively high. When several other processes which are less
the first vinous fermentation has completed itself, these, and about which some greater d
it is customary, in the wine-growing countries, to opinion may possibly prevail; and one d
put the still active liquid into casks, and the slower monest, not only amongst wine-makers ba
process of fermentation then goes on, which lasts a amongst wine consumers, is the process
considerable time. During this second fermenta- In order to establish the effect and the
tion, there is very much the same kind of condition this process, I think we must trace bee
present as in the first, and there is always formed, of wine from the time in which it is firs
in this subsequent fermentation, a considerable casks by those who produce it, to the time a
quantity of deposit, which is afterwards removed it gets into the hands of the consumers.
with much care: either the supernatant liquid is tomary-I cannot say whether it is mivers!
carefully decanted, or, in some cases, it is removed but I believe it to be so almost-to pat
by a process of rongh filtration. The subsequent into new casks; and in the better distr
treatment of the wine, I mean the keeping of it in casks are used. New wood is far more pr
casks or cellars, and the subsequent keeping in old wood, when used for such a purpose: £
bottles--and these two processes of keeping it in course the wine, when put into the cask,
casks and keeping it in bottles are quite distinct the wood, so that the outer surface is f
these are not usually considered as forming part and allows some of the water and alcohol,
of the process of wine-making. It appears, how
ever, from the investigations of M. Pasteur, that the wine diminishes during the first year a
various volatile materials to evaporate. I
materials by these processes which really are as But this is not all. Whilst the water
essential to the composition of the product as any are evaporating from the outer surface of
other part of it, and that they ought to be con solved by the liquid which is in the w

conditions such as that air has access to the sub- changes take place in the composition and the in wood very rapidly, by a process of eva

stance. No actual wine or beer-making has yet been performed on a large scale on such conditions as to exclude oxygen. On the other hand, the es

it is necessary. In some cases, however, in wine-making. In fact, the process of wine-keeping is, in the body of the wine in the cask; and what w periments of Gay-Lussac established clearly that sidered as later parts of the process of wine- actually diffuses itself through the wet wood making, it has been thought desirable to facilitate theory, not to be separated from the process of than this, the water and alcohol which go out wine-making, the keeping being a process making it replaced by something. The cask does not eldar the fermenting vessels. Common experience cor- The wood is always sufficiently leaky for

* Cantor Lectures delivered before the Society of Arts

by PROFESSOR A. W. WILLIAMSON, F R.S.

nto it, and there is always space left the wine. Wine-makers are, therefore, in it of filling up their wine casks periodically. e districts in France, they are filled up in the ar three times, at three different periods; the second year, they are filled up only but only at perfectly definite periods or seahich have been found, for those particular to be most advantageous. But each time e, if examined carefully, is found to have oue, not only what we chemists should call ess of concentration, the solid substances disin the liquid of course always remaining behe proportion of liquid being diminished, the same time, it has undergone other s, that is, there is a deposit formed from it. of the bodies present in it, either by themor by forming compounds with others, added a, form a sediment, and in the wine-growing s it is customary, and I have no doubt neceso decant the wine and pour it off carefully e deposit many times, for the presence of posit, if continued in the wine, would be into the future changes which it has to underWhen this comes into the hands of the conthere is suspended in the substance of the zomo of this deposit-some solid particles might be got to settle down, but which could sily be removed completely by any process of absidence, and the processes of fining, which ceedingly various, have for their object the omplete removal of these solid particles by g compounds with them.

(To be continued.)

ammonia, and requiring to part with some of its
carbon to form the normal constituents of plants.
It is often a matter of interest to the microscopist
to say whether organisms, occupying a sort of
border-land, belong to the animal or the vegetable
kingdom, and in many cases this cannot be done
with precision or certainty. Some remarks of
Boussingault will assist us to arrive at right con-
ceptions of these matters. They will be found in a
paper read before the French Academy, in 1864, on
Vegetation in Darkness." He pointed out that
the natriment contained in seeds and in animal eggs
was of the same description:—

Albumen.

Fatty matters.

Milk sugar, glucose?

EGGS.

the marsh air, and believed that an ague with which he was twice attacked was occasioned by inhaling them-the fit coming on after having involuntarily smelt water in fermentation and covered with the plants and their spores.

The valuable researches of M. Pasteur and others into the cause of silkworm diseases are too well known to need extensive reference, and by the methods he proposed of obtaining eggs from healthy moths kept in seclusion, an enormous gain has been secured to the cultivators. M. Pasteur distinguishes three principal silkworm diseases, muscardine produced by spores of Botrytis Bassiana, and pébrine produced by "corpuscles," found in all stages from the egg to the moth, in all its tissues and liquids, in the silk material, and in the dejections. These corpuscles, he tells us, multiply by germs, but those which are found in the dust and rubbish of silk

Sulphur, phosphorus, entering into organic com- farms, he says, are dried up and deprived of life.

pounds.
Phosphate of lime.
Water in great proportion.

Albumen.

Fatty matters.

SEEDS.

Those which find their way into eggs are active for mischief. They may be introduced by birth and descent, by inoculation, or by food. Another disorder, called la flacherie, is produced by a ferment which develops chaplets of beads. These bodies have their origin in a fermentation of the mulberry-leaves. The investigations of M. Pasteur es

Starch, dextrine able to form glucose.
Sulphur, phosphorus, entering into organic com- tablish the fact that bodies belonging to the class of
pounds.

Phosphate of lime.

Water in small proportion, cellulose.

The seed requires moisture and oxygen from the air, and its mode of germination is analogous to the incubation of the egg. Citing the "Statique des Etres Organisés" by himself and M. Dumas, he observed:-" We said (in 1841) at certain epochs, and in certain organs, the plant becomes an animal; that like an animal it becomes an apparatus for

OME RECENT INVESTIGATIONS INTO combustion; that it burns carbon and hydrogen;

that it produces heat; that the sugar, or starch con
verted into sugar, furnishes the first materials by
which this character is developed. The experi
ments I now bring before the Academy complete
this statement by showing that a plant developed
in the dark, with stem, leaves, and roots, behaves
like an animal during the whole duration of its
existence." M. Boussingault proceeded to show
that while the animal, in addition to emitting heat
and carbonic acid in respiration, modified by
respiratory combustion a portion of the albumen it
consumed into the nitrogenous crystalline compound
urea, the plant growing in the dark transformed
part of its albuminoid matter into a crystalline prin-
ciple, asparagin, an amide like urea, and transformed
into aspartate of ammonia with as much facility as
urea becomes transformed into carbonate of
ammonia. This asparagin is found in the juices of
the cells, and thus differs from urea in not being an
excretion. While the higher plants are not so
sharply and completely separated from the animal
kingdom as was formerly supposed, we must not
be surprised if organisms belonging to, or related to
fungi, and whose mode of nutrition bears strong
resemblance to that of animals, should often be
difficult to classify; and similar difficulties are ex-
perienced in dealing with some of the lower
organisms living in ocean depths, and which seem
to perform the functions of plants.

ferments can be causes of disease, and they afford a striking instance of the value of the microscope in detecting such causes, and checking their action. The chief silkworm diseases arise from objects which the microscopist furnished with the data supplied by Cornalia, Quatrefages, and Pasteur can recognize with certainty, but the same cannot be said of other bodies known or supposed to have morbific properties, some of which are alike in appearance, while others, more susceptible of discrimination, bewilder an investigator when he tries to trace certain consequences back to them as an efficient cause.

46

"Hal

Dr. Burdon Sanderson considers it probable that every kind of contagion consists of particles;" but then come the questions of what are these particles? What is their origin? and how can we discriminate one from another. Referring to Hallier's researches and discovery of colonies of micrococci in every contagious liquid, he observes:-Assuming this observation to be correct, and that, as Hallier believes, the microzymes are identical with the contagious particles, it is of no value as a means of distinguishing the various contagia from each other, unless the micrococci are capable of differentia tion;" which last words seemed to be used inadvertently for susceptible of discrimination. lier," he continues, "admits at once that no specific distinctions can be founded on their forms or appearances, as actually observed in contagious liquids. He seeks for the required characteristics in their development, and maintains that, although the microzymes of two different classes are exactly the same, the higher forms to which they severally unfold are specifically distinct." He goes farther than this: from the higher forms obtained by cultivation he claims to be able to reproduce contagious microzymes. Dr. Sanderson does not consider that Hallier has proved his case, and this seems to be the general opinion in this country; but what is here said may induce Fellows of this Society to make experiments with the lower forms of life, and work out disputed or doubtful points of fungoid development. Among the fungi to which Hallier imputes disease is the Pleospora herbarum, the form that is parasitical on darnel being in his opinion the cause of sheep-pox-a thing which Dr. Sanderson observes has not been tested by actual experiment.

MINUTE ORGANISMS.* (Concluded from page 585.) VERTING to the action of ferments, it may be remarked that fermentation was the subsome lectures delivered by Dr. Williamson. Terence to the microscopy of the organisms ned in process of fermentation, they can ly be considered as up to date, but it may Il to glance for a moment at the "conclusive" is alleged by the Professor for ranging the nts amongst animals rather than plants. Dr. mson says:-"These organisins assimilate, use a homely phrase, they feed upon very ex substances; they give off during their vital ons less complex substances." Another reason nsidering them animals, he states to be, "that as plants require for their growth the light of an-in fact, their very growth is a process of ption of heat by their leaves from the rays of an-and plants by so doing render heat latent, sometimes express it, that is, they cause an rent disappearance of heat, and lower the erature of surrounding space; animals, on the ary, give off heat during the exercise of their functions, and do not need to be exposed to or to continuons light for their growth." This rely an astonishing passage, and physiologists feel compelled to demur to the assertion that is not necessary to the performance of the The connection of minute organisms of the nature functions of animals, and that animals in of ferments with disease has occupied attention ral could live without light. If animals gave during the past as in preceding years. Dr. Lionel all the heat they wanted, by their own pro- Beale, in a paper published in a recent number es, we might in this cool climate simplify of the Monthly Journal, protests against the thing, abandon the domestic winter fire, and opinion entertained by Mr. Simon and many others, >>r have our benevolent sentiments shocked by that each contagions disease is produced by a of fellow-creatures frozen to death. It is cer-specific vegetable organism;' and he says it ly an error to say that "animals do not need to appears to him that the arguments break down as xposed to heat," and also to represent plants soon as they are analyzed, and the facts in their Whether we call the organic particles in question imply heat consumers, and not also heat pro- favour carefully investigated. Dr. Beale refers the "bioplasts," or "microzymes," whether we supcers. Mr. Grove, in his "Correlation of Physical mischief to minute living particles of "bioplasm," pose them animal or vegetable, and whatever ces," says, "Heat is an immediate product of and he says, "these resemble one another in gene- theory we form as to their origin, there are mical affinity. I know of no exception to the ral appearance. Neither by its form, chemical three conspicuous modes by which they may eral proposition, that all bodies in chemically composition, or other demonstrable properties, become disseminated, viz., by water, abining produce heat." It is from this general could the vaccine germ be distinguished from the that plants do evolve heat in their processes of small-pox germ, or the pus germ from either. All abination, and at times they evolve enough to resemble the minute particles of the bioplasm of the Juce a striking elevation of temperature, as is blood from which they have probably been derived, l known. It cannot be affirmed of all fungi, but from which they differ so remarkably in power." ing as ferments, that they feed upon complicated The doctrine of absolute species propagated by bstances, though some do; and on the other special germs capable of no other development than nd, the food of other plants is not at all times, one having correlation with a particular disease in d always simple. For example, in the last edition volves difficulties which require great consideration Dr. Carpenter's "Principles of Human Physio- on the part of naturalists and physiologists, and is gy," edited by Mr. Power, I find an allusion thus obviously connected with questions of the perade to a paper by Risler, "On the Absorption of manence of species, and the production of varieties. umus by Plants," and on the functions of ordinary It may be doubted whether all living particles in ants as compared with those of Fungi:-"The plants, or which are plants, conld be distinguished chalation of carbonic acid is not peculiar to fungi by any means with certainty from Dr. Beale's germinating embryos, for it takes place during animal bioplasm particles; and we are not without e whole life of flowering plants, both by day and recurring evidence that vegetable organisins may be ight, in sunshine and in shade, and from their reen as well as from their dark surfaces. And it causes of disease. Dr. Balestra has lately adduced reasons for supposing that a microscopic plant pros not improbable that, as in the case of fungi, its ducing an appearance like oil spots on the water of and also whether microzymes, which under some ource lies partly in the organic matters absorbed; the Pontine Marshes, and which, on examination, ecent investigations having rendered it probable is found to have a form like that of the Cactus hat plants really take up and assimilate soluble Peruviana, is the source of ague poison. He de umas." Now soluble humus is a highly complex scribes its spores as 1-1000th of a millimètre in ubstance, probably consisting of various acids and diameter, and of a characteristic form. He found that small quantities of sulphate of quinine and arsenious acid or sulphite of soda altered them in a striking way and killed them. He traced them in

By Mr. SLACK, Sec. R.M.S. The annual address
Jelivered before the Royal Microscopical Society.
Now publishing in these columns.

or by air, or in food either liquid or solid. The Yearly Report on Public Health," by Mr. Simon, published last year, contains a paper by Dr. Thorne, "On the Effects produced on the Human Subject by Consumption of Milk from Cows having Foot-and-Mouth Disease," and his conclusions are that "a disease appears sometimes to have been produced in the human subject when the milk of cows suffering from the disease has been freely used without being boiled;" but he adds, "in a very large number of cases the milk of cows undoubtedly affected has been used without producing any noticeable marked effects." This seems to be analogons to the well-known fact that persons or animals exposed to contagion do not always catch the diseases which those contagions are supposed competent to produce; and this suggests the important inquiry as to what conditions the contagions require for their mischievous activity, circumstances produce disease by their processes of growth or development, can develop under other conditions without inducing such results. In the case of cow's milk infected with germs of foot-andmouth disease, Londoners have been supposed to have derived advantage from the well-known prac tice of the trade to distribute their article in the mild form of milk and water; but the addition of