The Progressive Rate of Error of the Hydrographic Office pattern Thermometers, as deduced from the foregoing table, by testing-apparatus, is by Casella, equal to an increase of effect at the rate of o°014 per 250 fathoms' pressure; and by Pastorelli, equal to a decrease of effect at the rate of 0° 044 per 250 fathoms' pressure.

Thus, while one set of thermometers show an increase of effect under pressure, the other set denote a decrease, and the mean of the two would be so small a decrease as not to be appreciable; and the practical conclusion is, that, by the testing-apparatus, the elasticity of the glass is in exact proportion to the pressure applied.

OCEAN OBSERVATIONS BY STAFF-COMMANDER
E. K. CALVER

Although from the result of the experiments with the testing apparatus, a scale could be formed for the correction of the Hydrographic Office pattern thermometers, that scale may be said to be made under theoretical conditions rather than practical, and as it was necessary to verify its correctness by observations in the ocean, a number of the instruments used in the press were sent on board the Porcupine in 1869, and a series of most carefully taken observations were recorded by Staff-Commander Calver at the same depths as the calculated pressure applied in the press.

It is unnecessary to give the details of these observations; it will suffice to give the progressive error derived from the mean of them, and corrected for the error of the standard.

Per 250 fathoms

Press.

Error.

Pressure.

Press.

Ocean.

Ocean.

By this comparison, although the errors, as found by the two modes of observation, differ at individual depths or pressure, still the means of Casella's per 250 fathoms are almost the same, and those of Pastorelli's differ only three-tenths of a degree in 2,000 fathoms, the extent to which the comparison can be made.

There can be little doubt that, without the aid of the Miller pattern, by an extended series of observations a scale could have been obtained to correct the Hydrographic Office pattern to a very close approximation of the truth (in accordance with the proposed first intention of the experiments); but the timely suggestion of Dr. Miller has quite set at rest any difference of opinion as to the instrument for future use.

OYSTERS IN IRELAND*

HIS IS Excellency the Lord Lieutenant of Ireland having had represented to him that the artificial propagation of oysters was imperfectly understood in Ireland, appointed in October 1868 Messrs. Blake, M.P., Francis, Hart, and Brady, commissioners to inquire into and report on the artificial cultivation and propagation of oysters. The instructions to the Commission were to visit the principal places in France, England, and Ireland, where oyster cultivation is or can be carried on, to examine the best authorities on the subject, and to ascertain as far as possible the causes which have led to failures. It was also hinted that three weeks would suffice for Ireland, a

* Report of the Commission appointed to inquire into the Methods of Oyster Culture in the United Kingom and France, with a View to the Introduction of improved Methods of Cultivation of Oysters into Ireland. (Presented to both Houses of Parliament by command of Her Majesty.) Dublin, 1870.

fortnight for England, and the same amount of time for France. The Commission proceeded in October 1868 to France to commence their fortnight's tour, and in June 1870 presented their report, which has now been laid before Parliament. The Report occupies about fifty pages; and 150 more are very usefully taken up with a series of appendices. Ten plates are also included in the volume.

The

The Report commences with a list of the places visited by the Commission, from which we notice the omission of Dub in Bay, although Howth and Malahide had each at one time a respectable name for oysters. It then proceeds to give the natural history of the oyster, which we pass over without further comment than that it is a pity the Commissioners did not consult some person tolerably skilled in malacology ere they printed it-to criticise it would be but to break a butterfly on a wheel. various branches of oyster fisheries are well described, and an interesting epitome is given of Coste's labours. It would appear that the great bulk of the oysters bred at Arcachon are sent to Marennes and Tremblade, where the green tint, so much esteemed in France, is imparted to the beard of the oyster. Such a prejudice exists in England against this green tint, that the Essex oysters are largely exported to France. It should be recollected that oysters impregnated with copper have always a greenish tinge of body, while those with green beards do not owe their colour to copper but to their peculiar feeding. The reporters suggest that the Diatomaceæ are probably the cause, and give figures of some Diatoms, to which we would call the attention of Dr. Donkin, who is writing a monograph of this group; to say the least, they are very comical.

The diminution in oyster production which has taken place in England, though very considerable, is not so great as in France. The Hayling Island enclosure is described, and plans of the beds given. The various methods of oyster culture are described, and appropriate places for their cultivation are pointed out. In reference to this portion of the subject, we may refer to the elaborate report on the temperature of the surface of the sea on the coasts of Great Britain, Ireland, and France, by Prof. Hennessy, in which he deduces that :

"1. The temperature of the sea on the coast of Ireland varies within narrower limits than on the coast of Great Britain, or, in other words, it is more equable throughout the year and also during the summer season, when oyster breeding takes place.

"2. The temperature of the sea at noon on the Irish coast, especially on the south and west coasts during the months of June and July, is, upon the whole, higher than on the coast of Great Britian, and less than on the west coast of France.

"3. This temperature seems to be sufficient for the requirements of oyster breeding, and therefore, a fortiori, the temperature about two in the afternoon under the conditions above referred to.

"4. The highest temperature of the seas surrounding Ireland, and probably also of those surrounding Great Britain, is during the month of August, and the least during the month of February.

"5. Any advantages as to temperature possessed by the seas which wash the Irish coast are unquestionably due to the thermal influence of currents connected with the Gulf Stream."

Prof. Sullivan also appends an important Report on the Composition of the Soils of Oyster Grounds, and on the qualities which exert most influence on oyster cultivation, and comes to the conclusions :

"1. That the influence of the soil upon the breeding and growth of oysters is complicated by: temperature, especially during the spawning season; sudden alternations of heat and cold, due to currents; alternation of depth of water, especially as regards whether the maximum of sun-heat and

light concords with low water during the spawning season; velocity of tide, angle of inclination of shore, &c.

2. That the soil of oyster grounds may be made up of materials of any of the great classes of rocks, arenaceous, argillaceous, or calcareous, provided they contain

"3. More or less of a fine flocculent highly hydrated silt, rich in organic matter, which indicates that Diatomaceæ, Rhizopoda, Ínfusoria, and other mirute creatures abourd.

4. That the character and abundance of such small organisms in a locality seems to be the true test of a successful oyster ground.

"5. And lastly, that although oysters do undoubtedly assimilate copper from water where mine-water containing traces of that metal flows into the sea in the neighbourhood of the oyster beds, the copper is chiefly, if not exclusively, confined to the body of the oyster, and does not appear to reach the mantle or beard. That the so-called green oysters of Essex, Marennes, and other places, on the other hand, are green-bearded and contain no copper, nor can the most minute trace of copper be detected in the soil of the oyster grounds where such greenbearded oysters are produced."

The Report concludes with the following recommendations :

66

"I. That all regulations with regard to the close time around the Irish coast should be strictly maintained.

"2. That the inspectors of Irish fisheries should have power, whenever they determine to reserve a bank or any portion thereof from public dredging for the purpose of recovery, to make such arrangements as may seem desirable for keeping the restricted part free from weeds and

'3, That there should be procurable at each coastguard station, at a small cost, general information as to oyster culture, and simple instructions as to the best modes of proceeding.

66

4. That the inspectors be empowered to adopt such other means as they may deem necessary to afford information and instruction to those requiring it with respect to oyster culture.

"5. That having unsizable oysters in possession in places where it is prohibited by any bye-law to take oysters from any public beds under a certain size, shall be prima facie evidence that such oysters were taken in places so prohibited; such regulations not to apply to private oyster grounds.

"6. That facilities be afforded to the coast population to acquire the use of small portions of foreshore, or sea bottom, for oyster cultivation, and to obtain loans on satisfactory security for the preparation of same, and for the purchase of oysters, collectors, &c.

"7. That landed proprietors desirous of cultivating oysters on the shores adjoining their lands, be empowered to avail themselves of the provisions of the Irish Land Improvement Acts, for the purpose of oyster cultivation." We would commend the perusal of this Report to those interested in this subject; of its importance there can be little doubt; and while we agree with the commissioners that no very extraordinary profits are to be made out of oyster culture, and that hence it is not a subject for extensive commercial speculation, yet we know of none more deserving of the attention of those interested in the general welfare of this country.

ARTIFICIAL MILK

E. P. W.

AMONG the many sorrowful records of the Siege of Paris, one of the most enduring, and not the least touching in its melancholy eloquence, is afforded by the

There is another series of papers of equal, if not greater significance, viz., those on the utilisation of strange materials for food, the economising of waste nutritive materials, and their substitutive uses.

The investigations on these subjects have led to more practical results than the papers on aërostation. This has been especially the case with the researches that are described in the papers of M. Boillott, M. Dubrunfant, and M. Charles Fua, on "Alimentary Fats."

Alimentary fats " is a wide expression, including some rather unsavoury hydro-carbons and very curious refuse materials. The main object of these investigations was to determine how such substances may be "usefully employed in alimentation," or, in plain unsophisticated English, how to make butter from candle-ends, dirty dripping, colza oil, fish oils, the refuse of slaughter houses, the restored grease of the wool-dresser, &c. The general result has proved that the "frying process"-which was not altogether unknown to certain enterprising Englishmen before the investment of Paris-is triumphant over all its rivals; that by simply raising the fat to 140° or 150° Centigrade, and in the mean time cautiously sprinkling with water, the cellular tissue, the volatile oils, the rancidity, offensive odours, and all other non-sentimental impediments to "alimentation," are removeable.

This frying process has already effected something like a revolution in the industry of soap-boilers, some of whom have changed their trade to that of butter-fryers. We may thus explain the remarkable fact that, although the excessively dry summer of 1870 reduced the dairy produce of England to about half the average, and had nearly the same effect on our other sources of cow-butter supply, there was no material reduction in the supply or consumption of fresh butter for the London and Provincial markets during the following winter, the only notable disturbance which occurred being in the demand for kitchen-stuff and empty Dutch butter-tubs.

M. Dubrunfant is not content with superseding the cow in the mater of butter, but has subsequently made similar attempts upon milk. He proceeds in a strictly scientific manner, commencing with the following summary of the results of Boussingault's analysis of cow's milk:

Nitrogenous material (caseine and albumen)
Fatty material (butter)
Sugar (of milk)

Salts

00337

00376

0.0567

Quoting the observations of Payen and others which show that milk is alkaline, and owes its alkalinity to soda, he proceeds to refute the theory of churning which has been generally adopted by microscopists, viz, that the fat globules in milk are invested with a delicate membrane which is ruptured in the churn, and thereby permits the agglomeration of the fatty material into butter.

M. Dubrunfant contends that milk is simply an emulsion of neutral fatty matter in a slightly alkaline liquid, such as can be artificially imitated; and that the process of churning consists in hastening the lactic fermentation, thereby acidifying the serum of the milk, and at the same time agglomerating the fatty matter which the acidity sets free from its emulsion. He further controverts the cellular theory by showing that the fat globules of milk do not display any double refraction, as do all organised membranous tissues.

Having thus examined the theoretical constitution of milk, he proceeds to the practical method of imitating it,

and gives the following directions: Add to half a litre of water forty or fifty grammes of saccharine material (cane sugar, glucose, or sugar of milk), twenty or thirty grammes of dry albumen (made from white of egg), and one or two grammes of subcarbonate of soda. These are to be agitated with fifty or sixty grammes of olive oil or other comestible fatty matter until they form an emulsion. This may be done either with warm or cold water, but the temperature of 50° to 60° C. is recommended. The result is a pasty liquid, which, by further admixture with its own bulk of water, assumes the consistency and general appearance of milk.

Luxuriously-minded people who prefer rich cream to ordinary milk can obtain it by doubling the quantity of fatty matter, and substituting two or three grammes of gelatine for the dry albumen. The researches of Dumas and Fremy having reinstated gelatine among the nitrogenous alimentary materials, M. Dubrunfant prefers gelatine to albumen; it is cheaper, more easily obtained, and the slight viscosity which it gives to the liquid materially assists the formation and maintenance of the emulsion. He especially recommends this in the manufacture of siege-milk," on account of the obviously numerous articles from which gelatine may be obtained.

The uses of artificial milk need not be limited to supplying the wants of the residents of besieged cities. As an ordinary element of the human breakfast table, it is not likely to supersede the product of the cow, but calves are suggested as being superior to vulgar human prejudices. In the ordinary course of rearing, these animals demand a large proportion of the milk of their mothers, and are commonly ill-fed or prematurely sacrificed on that account. By feeding them luxuriously on artificial milk (which may be still further cheapened by using colza oil, which has been rendered tasteless and alimentary by the frying process above described), the milk, butter, and cheese of the cow may be considerably economised, and the supply of veal improved both in quantity and quality, by keeping the calves a much longer time before they are killed. I might make further suggestions in the direction of "dairy-fed pork," &c., but this is unnecessary, the commercial instinct is sufficiently strong to avail itself of all such cheapening applications of science. Those who are professionally engaged in detecting the adulterations of food will do well to study the physical peculiarities by which M. Dubrunfant's milk may be distinguished from that of the cow, both in the ordinary and condensed form. By substituting vegetable albumen for the white of egg or gelatine, the vegetarian may prepare for himself a milk that will satisfy his uttermost aspirations.

W. MATTIEU WILLIAMS

NOTES

THE following telegrams have been received from the Eclipse Expedition since our last :-" MANGLORE, Wednesday, Dec. 6.— We have landed here from the flagship; all well. The Government arrangements are admirable. The weather is promising. The parties are posted as arranged." From N. R. Pogson, at Avenashy, to the Astronomer Royal, Royal Observatory, Greenwich:-"Weather fine; telescopic and camera photographs successful; ditto polarisation; good sketches; many bright lines in spectrum.-Dec. 12." From Colonel Tennant, F.R.S., Dodabeta, Ootacamund, to W. Huggins, F.R.S., Dec. 12, 9.15 A.M. :-"Thin mist. Spectroscope satisfactory. Reversion of lines entirely confirmed. Six good photographs."

AT the meeting of the Geological Society on the 6th inst., the President announced the bequest to the Society, on the part of the late Sir R. I. Murchison, of the sum of 1,000l., to be invested in the name of the Society or its trustees, under the title of the "Murchison Geological Fund," and its proceeds to be annually devoted by the Council to the encouragement or assis.

tance of geological investigation. The donation of the proceeds of the fund was directed by the testator to be accompanied by a bronze copy of the Murchison Medal.

Ar the meeting of the Royal Geographical Society on Monday last, Sir Henry Rawlinson stated that the Council intended to address the Foreign Office, with a view of arranging, either directly from the Foreign Office, or through co-operation between the Foreign Office and the Society, some means of communicating with Dr. Livingstone, either by sending messengers into the interior of Africa, and offering a reward of 100 guineas to any African who will bring back a letter in Dr. Livingstone's handwriting to the sea-coast, or by organising a direct expedition, headed by some experienced and well-qualified European, who should himself penetrate to the point where Dr. Livingstone is

supposed to be.

By a decree, dated April 18, 1866, of the Minister of Public Instruction in France, a prize of 50,000fr. (2,000l.) was offered for the most useful application of the Voltaic Pile, the period for competition to expire in April 1871. From a report of the minutes presented by the President of the Republic, it appears that candidates are few in number, and that in the opinion of the savants to whom the memoirs were submitted, none is of sufficient merit to have earned the prize. By a decree of the 29th of November, the competition is now extended for another period of five years, to terminate on November 29, 1876.

WE learn from the Lancet that the promoters of the scheme for commemorating the life and labours of John Goodsir, late Professor of Anatomy in the University of Edinburgh, have got only 700/. instead of 2,000/., and have had to relinquish the idea of a fellowship, and adopt that of a triennial prize, to be open to all graduates of the University of not more than three years' standing, to be given for an essay or treatise containing the results of

original investigations in anatomy, human and comparative,

either normal or pathological, or in experimental physiology. The Acting Committee of the Association for the better Endowment of the University of Edinburgh have prepared the deed of endowment for the Syme Memorial. The capital sum amounts to 2,500/.; whereof 2,000l. were paid over to the Association by the Syme Memorial Committee, and 500%. was added by the

Association.

THE Council of the University of Edinburgh has decided to take into consideration on the 21st inst. the appeal against the decision of the Senate as to rescinding the regulations for the education of women in medicine.

THE Examiners in the Natural Science School at Oxford (W. Ogle, M. D., Corpus; J. A. Dale, Balliol; and R. H. M. Bosanquet, St. John's) on Saturday issued the subjoined class list :Class I.-H. A. Black, Christ Church; W. T. Goolden, Magdalen; E. H. Jacob, Corpus; A. S. L. Macdonald, Merton; J. A. Ormerod, Jesus; A. G. Rücker, Brasenose; S. H. West, Christ Church. Class II.-E. H. Forty, Christ Church; J. Turner, Exeter; J. L. Twynam, St. Mary Hall. Class III.— Nil. Class IV.-Nil.

MR. W. A. BRAILEY, who was second in the Natural Sciences Tripos at Cambridge, has been elected a Fellow of Downing College in that University.

M. Georges Delaporte, engineer of M. Tessié de Motay's Oxy-hydrogen Light Company, has been nominated a Chevalie

of the Legion of Honour, as an acknowledgment of the services rendered to the State during the Siege of Paris in the application of the Electric Light to strategic operations.

THE Lord President of the Council has nominated Mr. T. S. Aldis, formerly scholar of Trinity College, Cambridge (Second Wrangler in 1866), to be an Inspector of Schools.

The following are now announced as the probable arrangements for the Friday evening meetings at the Royal Institution before Easter 1872-January 19, Mr. William R. Grove, F.R.S., on Continuity; January 26, the Archbishop of Westmin ster, on the Demon of Socrates; February 2, Prof. Odling,

F.R.S., on the new metal Indium; February 9, Prof. Ilumphry, F.R.S., on Sleep; February 16, Dr. Gladstone, F. R. S., on the Crystallisation of Silver and other Metals; February 23, Mr. Henry Leslie, on the Social Influence of Music; March 1, Mr. C. W. Siemens, F.R.S., on Measuring Temperatures by Electricity; March 8, Mr. R. Liebreich, on the Effect of certain Faults of Vision on Painting, with especial reference to Turner and Mulready; March 15, Mr. John Evans, F.R.S., on the Alphabet and its Origin; March 22, Prof. Tyndall, F.R.S.

WE learn from Les Mondes that the lamentable disagreement between M. Daubrée, the director of the mineralogical department of the Museum of Natural History at Paris, and his assistant, M. Stanislas Meunier, is now happily terminated, and that the latter is again permitted to carry on his researches at the Museum.

THE Exhibition of the Photographic Society, held in its rooms in Conduit Street, closed on Saturday last. While among specimens of portraits the works of Grasshofer of Berlin, Rylander of Paris, and other Continental artists, challenged comparison with any of our home productions, there can be no question that in

landscape photography, the exquisite workmanship of Bedford,

Robinson, Cherrill, and some other English photographers, easily bore off the palm. There were some very fine specimens of Edwards's heliotype process, as well as of the autotype and other carbon-printing processes.

WE learn from the American Naturalist that the State Micro

scopical Society of Illinois has issued a prospectus of The Lens, a Quarterly Journal of Microscopy and the Allied Natural Sciences; with the Transactions of the State Microscopical It will be an octavo, each number containSociety of Illinois.

ing at least forty-eight pages of reading matter. Terms, 2 dols. The editor will be Mr. S. A. Briggs, per annum in advance. 177, Calumet Avenue, Chicago. Though its appearance has been delayed by the fire, we learn that it will soon be issued.

AT a recent meeting of the Asiatic Society of Bengal Mr. W. T. Blanford exhibited a collection of chipped quartzite implements found about forty miles west of Bhadrachalam, on the Godávarí. The thirty-five specimens exhibited were all found within a space of about fifty yards square, and at least as many more were rejected on account of being badly made. The place where they were found was in dense jungle, the rock soft sandstone, and the implements, as was usually the case in Southern India, had evidently been chipped from pebbles. Several were formed of white vein quartz, an unusual circumstance. The forms of these implements were those of the kind most frequently found in French and English gravels, and they varied from about 3in. to 6in. in length. That the spot where they were found was a place of manufacture was probable, not only from the occurrence of ill-formed implements, but also from flakes, evidently chipped from the quartzite being abundant.

A VERY beautiful and extraordinary Aurora Borealis was witnessed at Montreal on November 21. The following account of