clude that, contrary to the opinion of Carius, the compound of sulphur and chlorine analogous to water does actually exist as an extremely unstable body, readily parting with a portion of its chlorine on being gently heated.

Deacon's Chlorine Process as applied to the Manufacture of Bleaching-powder on the larger Scale. By HENRY DEACON.

On Sorbit. By Professor DELFFS, of Heidelberg.

Twenty years ago M. Pelouze (Ann. de Chim. et de Phys. 3 ser. xxxv. p. 222) discovered a crystallized substance in the fruits of Sorbus aucuparia which he called Sorbin. Since that time very few chemists have paid attention to this substance, and, as far as I know, nobody in my country has succeeded in preparing it again. The principal of one of our greatest manufactories of chemical preparations, to whom I addressed myself, told me that he never found the least trace of the said substance, although he had worked up large quantities of the abovementioned fruits for preparing malic acid; and to the same result came M. Byschl (Buchner's N. Repert. der Pharm. iii. p. 4), who asserts that there is no ready formed sorbin in the ripe berries of Sorbus aucuparia. In my two first attempts to procure sorbin I also failed; but during last year I succeeded, and at the same time I became aware of the reason of my previous failures. When I first tried to get sorbin, I thought it advisable to combine the preparation of malic acid with the process given by M. Pelouze for getting sorbin, and therefore I separated the former by means of acetate of lead. This is the reason, I think, which has prevented the success of myself as well as of other chemists in the preparation

of sorbin.

I will not repeat the method of forming sorbin given in all manuals of chemistry; it is sufficient to say that, when I kept strictly to the prescription of M. Pelouze, I got a large quantity of beautiful crystals, a specimen of which was contained in the tube exhibited. After I had got these, I tried to obtain the malic acid from the residue, but I found that the malic acid had quite disappeared. To this I must add that the alcoholic fermentation which takes place after the juice of the berries of Sorbus aucuparia has been left a few days in a tepid place is more easily perceived by the formation of carbonic acid than by the smell of spirit of wine. I think it, therefore, not improbable that there is a connexion between the disappearance of the malic acid and the small produce of spirit of wine on the one side, and the formation of sorbin on the other. Suppose the malic acid, commonly called bibasic, and therefore apt to form a bimalate of ethyl (=C1 H30+ 2CH20'+HO), assimilates two equivalents of water to this compound, you will have then the equation

C'H 0+2C4 H2 O1+3HO=C12 H12 O12, the right-hand side of which gives the composition of sorbin.

As pertaining to the preparation of sorbin, I have only to add that the dark sticky ley in which the crystals are formed can very easily be separated by putting both on a brick. After a few days' repose the brick has absorbed nearly all the ley, and the pale yellow-coloured crystals of sorbin, if dissolved in water and left to spontaneous evaporation, become very soon colourless.

The sorbin belongs to the same group as the mannit, quercit, inosit, dulcit, picrit, &c.; and as the last syllable is always characteristic in chemistry, its name, I think, should be changed into sorbit.

Further experiments are required to prove if the supposed genesis of sorbit is true or not; but, in any case, I am convinced that there is no sorbin ready formed in the fruits of Sorbus aucuparia.

On the Detection of Morphine by Iodic Acid. By Prof. DELFFS. Among the poisonous alkaloids which in forensic cases most frequently give occasion for chemical investigations morphine occupies the first place. For its

detection a great many tests have been proposed, most of which, however, have little interest for the forensic chemist, particularly as they depend on phenomena which may also be produced by other substances beside morphine. It is not intended here to justify this assertion by a critical examination of all the tests for morphine which are liable to the reproach mentioned; it will be sufficient to signalize one of them, the iodic acid, as an example. The well-known property of this acid, of being reduced by morphine, is certainly adapted to distinguish the latter from other alkaloids, but is altogether insufficient to establish the nature of morphine, because there are a great many other substances, partly of organic, partly of inorganic origin, which likewise reduce iodic acid. Nevertheless I have found that iodic acid, with the aid of the microscope, presents a sure means of characterizing morphine perfectly, because the reaction between this alkaloid and the above-mentioned test proceeds under such peculiar appearances that morphine cannot be mistaken for any other substance. The process to be adopted for this purpose is the following:

After the morphine (of which the smallest particle is sufficient) is placed on a slip of glass and covered with a glass cover, as much water is added as will fill the space between the slip and the cover and extend a little beyond the margin of the latter. After the glass slip is put under the microscope and this is directed to the morphine, a particle of iodic acid is put into the water at the margin of the covering glass. In a few moments a great number of minute spherical yellow molecules, of constantly equal diameter, are seen to move in a direction from the iodic acid to the sides of the morphine, and soon form in its vicinity numerous colourless needleshaped crystals, mostly united so as to form tufts. For the observation of this microscopic metamorphosis a magnifying-power of 300 linear would be the most suitable; when a more powerful system of lenses is employed, the difference of the focal distances of the morphine and the above-mentioned molecules and crystals readily becomes too great for the distinct observation of the whole simultaneously. Hence it is also advantageous to place under the covering glass the thinnest possible fragment of morphine.

I reserve for another place a more detailed communication on this subject.

Experiments on Chemical Dynamics.

By J. H. GLADSTONE, F.R.S., and ALFRED TRIBE, F.C.S.

The authors had recently communicated a paper to the Royal Society in which they investigated somewhat minutely what takes place when a plate of one metal, such as copper, is immersed in a solution of a salt of another metal, such as nitrate of silver. They had shown that, while the silver was being deposited on the copper, an actual passage of the nitric element towards the more positive metal occurs, causing the formation of a dense solution of nitrate of copper inside the crystalline deposit, and a consequent downward current, and at the same time an upward current of almost pure water from the tips of the crystals. They had shown, also, that with solutions of different strengths the chemical action in a given period (say ten minutes) is not in direct proportion to the strength; but, cæteris paribus, twice the strength gives three times the chemical decomposition. This augmentation had been attributed to an increased conduction of the stronger liquid. In the present paper the authors exhibited these phenomena in a dissected form, and carried the observations still further.

Instead of the silver crystals being allowed to grow from the copper into the nitrate-of-silver solution, two separate plates were taken, one of copper and the other of silver. The copper plate was immersed in nitrate of copper, and the silver plate in nitrate of silver, while the two metals were connected by a wire, and the two liquids were connected by a porous cell. Silver crystals were gradually formed upon the silver plate, while the copper was dissolved; and at the end of some hours it was found that all the silver had been removed from solution, and that the loss of the copper plate was almost exactly what might be calculated from the amount of nitrate of silver originally placed in the other cell. The actual numbers were theoretical 0-412, actual 0-402. The copper nitrate was formed in

the cell with the copper plate, the specific gravity of the liquid having risen from 1-015 to 1.047.

A similar experiment was tried with plates of copper and zinc in sulphate of copper and sulphate of zinc respectively. The result was as before, metallic copper being deposited on the copper plate, and the sulphate of zinc rising in specific gravity from 1·123 to 1·139.

In order to determine whether the amount of silver deposited depended, not merely on the amount of the silver in solution, but also on the amount of copper salt that bridged over the intervening space, similar experiments were made in which the nitrate of silver was kept constant, but the nitrate of copper was increased by equivalent multiples. It was found that the silver deposited increased with the increase of the copper salt, being about double when the copper salt was seven times as strong, and that the effect of successive additions gradually diminished. This is in strict accordance with other experiments, showing that, when the copper plate is immersed in a mixture of the nitrates of copper and silver, the amount of silver deposited is increased, and increases with each successive addition of copper salt, though in a diminishing ratio.

That this acceleration is not produced by a copper salt only was proved by repeating the experiment with a variety of other nitrates.

The subjoined Table shows the results, and indicates, at the same time, that the increased effect does not depend simply upon the nitric element, which was present in the same quantity in all, but likewise on the nature of the salt.

Size of plate 3230 sq. millims.; volume of solution 72 cub. centims., containing 2.8 per cent. of nitrate of silver; temperature 18° C.; time 5 minutes.

On Crystals of Silver. By J. H. GLADSTONE, F.R.S.

The crystalline deposit on copper or zinc immersed in silver nitrate forms a very beautiful object when viewed under the microscope. The form, colour, and general character of it depend very much on the strength of the solution; if weak, say 1 per cent., the red metal is presently covered with a growth of small crystals, which are quite black; but as the action proceeds some of these crystals grow more rapidly than others, especially at the angles of the plate, and the new growth is white. If the solution be stronger, say 3 per cent., there is no black deposit, but the white silver simulates the appearance of furze-bushes or fern-leaves of varied structure. In much stronger solutions, say 12 per cent., the crystals reminded the author of juniper-branches, and in stronger still they had rather the outward form of moss. In nearly saturated solutions the crystals of silver end in thick knobs. The crystals at first advance pretty uniformly into the liquid, but when they have considerably reduced its strength, there usually happens a stoppage of the general advance, and a special growth from one or two points, forming long feathery crystals, that sweep rapidly through the lower part of the solution. In a 1 per cent. solution these are long meandering threads, with tufts like the dendritic appearances in minerals. The crystals are peculiarly beautiful when nitrate

of copper or of potassium has been previously added to the nitrate of silver, Some other forms were described as produced under peculiar circumstances, such as long straight threads, of extreme tenuity, often changing their direction at a sharp angle.

Note on Fibrin. By Dr. JOHN GOODMAN.

The author having read a paper on the above subject at the Meeting of the Association in Liverpool last year, has been since that period constantly engaged in a long series of experiments establishing the truth of the statements there set forth. The following is an epitome of the results obtained. The experiments were performed under the microscope::

1. Albumen immersed for some short time in cold water loses its characters as albumen, and becomes transformed into a substance which the author asserts exactly resembles blood-fibrin under the microscope.

2. This substance exhibits intense attractive powers.

3. It decomposes peroxide of hydrogen with effervescence. According to the author's views, all these experiments showed that water is the primary source of this change, and that until albumen is in some way subjected to the influence of water, oxygen can exert no influence in producing this change.

4. The rapidity or intensity of the transformation was not increased by raising the temperature of the water.

5. Ovalbumen does not per se become transformed into fibrin by the roltaic currents, only to such an extent as its water of fluidity is available for this purpose.

6. But when diluted with water the entire mass of albumen submitted to the current was rapidly transformed into fibrin.

7. When this substance was submitted to potash it dissolved in three minutes, whilst blood-fibrin required twelve hours and ovalbumen twenty-four hours for solution.

8. In strong hydrochloric acid both this substance and blood-fibrin dissolved in twenty-four hours, whilst ovalbumen was not completely dissolved in sixteen

days.

9. In all acid solutions of this substance, and of blood-fibrin precipitated by alkalies, and of alkaline solutions precipitated by acids, the author asserts that he invariably finds fibrinous rods and formations perfectly identical in their appearance one with the other, and without any coagulum peculiar to albuminous precipitations; whilst on the other hand in similar solutions of albumen similarly precipitated, he finds as invariably a dense flocculent coagulum, without the presence of fibrinous rods or other formations. Alkaline solutions, moreover, of albumen precipitated by acetic acid gave always a dense white and flocculent coagulum, and those precipitated by nitric acid gave a lemon-yellow precipitate, whilst neither white nor lemon-yellow coagula occurred in similar precipitations from like solutions of fibrin thus produced as blood-fibrin. The author maintains that these experiments show that the substance thus produced by the agency of water is genuine fibrin.

Preliminary Notice on a New Method of Testing Samples of Wood-Naphtha. By WILLIAM HARKNESS, F.R.M.S.

The detection of wood-naphtha, when present in alcohol, is now comparatively easy, but the converse problem, viz. the detection of alcohol in wood-naphtha, does not seem to have occupied the attention of chemists generally.

Methylated spirit, which is cheaper than wood-naphtha, is the only adulterant likely to be used, and any simple mode of determining its presence must be of some value to the chemist. One of the most common methods of examining a sample of naphtha is to ascertain its boiling-point; but this is not reliable, as different samples, even of the same specific gravity, may boil at different temperatures, varying from 138° F. to 156° F., and yet be free from ethylic alcohol.

The following method of testing samples was discovered by the author whilst

engaged in the preparation of oxalate of methyl. It was noticed that different samples of naphtha gave different quantities of this crystalline body. Further investigations showed that the presence even of a small quantity of methylated spirit or alcohol in the wood-naphtha from which the oxalate was prepared, altered in the most striking manner the temperature at which solidification took place. Thus, oxalate of methyl prepared from pure wood-naphtha is always solid at a temperature exceeding 100° F. This has been confirmed by experiments on all kinds of naphtha, English and foreign.

In samples containing methylated spirit or alcohol, crystallization always takes place at a temperature less than 100° F., such temperature depending on the percentage of alcohol present. The following are the averages of many experiments:Per cent. of alcohol in naphtha.

Oxalate of methyl

solid at or about.

104° Fahr.

0

5

10

15

20

30

95

86

76

64

49

The test is easily applied. Distil at a moderate heat 1 oz. of the suspected spirit, 7 drs. oxalic acid, and 1 oz. sulphuric acid; collect the crystals, if any, in a small beaker, and heat until the crystals melt, then with a thermometer watch the temperature at which crystallization again takes place.

One precaution is necessary: the sample examined, if not miscible with water, must be rendered so by filtration through charcoal previous to testing.

A Method of Preserving Food by Muriatic Acid.
By the Rev. H. HIGHTON, M.A.

As the great objection to preserving articles of food by chemical compounds is that it imparts a flavour to them more or less unpleasant, it occurred to the author to try whether they could not be preserved in the first instance by muriatic acid, and then before use be deprived of their acidity by means of soda or its carbonates. The author tried many experiments, and found that in many cases the plan might be employed with very good results, the muriatic acid not affecting the most delicate flavours, but leaving the article just as it was before, with only a slight not objectionable taste of common salt. There are two principal ways of effecting the object:

1. To dip the meat, fish, or other substance at intervals, if necessary, and expose it freely to the air to dry. During this process of drying the coating of muriatic acid prevented the approach of decomposition. Meat and fish thus prepared remained perfectly sweet for many months. The only thing necessary before using them was to steep them in a very dilute solution of carbonate of soda till any slight traces of the acid were neutralized.

2. The other plan is to enclose the substance in a close vessel with a small quantity of muriatic acid, so as to prevent evaporation. A very small quantity of muriatic acid seems to be sufficient to destroy the germs of decomposition-a quantity which, when ultimately neutralized by soda, gives a scarcely perceptible flavour of salt. A too large quantity of muriatic acid tends itself to decompose the substance submitted to its action.

One application of the plan was described. If meat be cut up small and steeped in weak muriatic acid, and when it is thoroughly penetrated boiled in a very dilute solution of carbonate of soda, carbonic acid is evolved in the pores of the meat, and splits it up into such minute fragments as to produce virtually a solution of the meat.