I^O 



NATURE 



[Dec. 14, 1 871 



Comptes Renins of the Academy of Science. The con- 

 struction, the filling, the guiding, and general management 

 of balloons, occupied so much of the attention of the 

 Academy, that, if all other records of the Siege were lost, 

 its date and effective duration might be pretty accurately 

 determined by the sudden appearance, the continuance, 

 and sudden cessation of these abundant papers on 

 aerostation. 



There is another series of papers of equal, if not 

 greater significnnce, 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 aerostation. This has 

 been especiallv the case with the researches that are 

 described in the papers of M. Boillott. M. Dabrunfant, 

 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 English- 

 men 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 sprink- 

 ling 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 daily 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) 0'0337 



Fatty material (butter) .... 0-0376 



Sugar (of milk) 0-0567 



Salts 0-0020 



Water 0-S700 



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 pennits the 

 agglomeration of the fatty material into butter. 



M. Dubrunfant contends that milk is simply an emul- 

 sion 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 einulsion. He further controverts the cellular 

 theory by showing that the fat globules of milk do not 

 display any double refraction, as do all organised mem- 

 branous 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 6o' C. is re commended. The result 

 is a pasty liquid, which, by further admi.Kture 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 nitro- 

 genous alimentary materials, M. Dubrunfant prefers gela- 

 tine to albumen ; it is cheaper, more easily obtained, and 

 the slight viscosity which it gives to the hquid materially 

 assists the formation and maintenance of the ernulsion. 

 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 sup- 

 plying the wants of the residents of besieged cities. As 

 an ordinary clement 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 fr>'ing pro- 

 cess 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 com- 

 mercial 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 telegi-ams have been received from the Eclipse 

 Expedition since our last : — "Manglore, Wednesday, Dec. 6. — 

 We have landed here from the flagship ; all well. The Govern- 

 ment arrangements are admirable. The weather is promising. 

 Tlie parties are posted as arranged." From N. R. Pogson, at 

 Avenashy, to the Astronomer Royal, Royal Observatory, 

 Greenwich: — "Weather fine; telescopic and camera photo- 

 graphs successful ; ditto polarisation ; good sketches ; many 

 bright lines in spectrum. — Dec. 12." From Colonel Tennant, 

 F.R.S., Dodabeta, Ooticamund, to W. Hugghis, 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 1,000/., to be in- 

 vested in the name of the Society or its trastees, under the title 

 of the " Murchison Geological Fund," and its proceeds to be 

 annually devoted by the Council to the encouragement or assis- 



