460 Proceedings of Philosophical Societies. [June, 



are in olcfiant gas, but combined with different proportions of water 

 reduced to its elements. 



In alcohol the elements of water form a third of the whole, and 

 in ether they form the fifth part; so that the action of sulphuric 

 acid upon alcohol to produce ether seems to consist only in de- 

 priving it of a portion of its water ; and the same acid, when 

 applied in greater quantity, produces defiant gas, by removing the 

 whole of the water. 



The analytical results of M. de Saussure agree with those ob- 

 tained by the late Count Rumford, respecting the quantity of heat 

 produced by combustion of alcohol and ether. 



One of the great difficulties in the analysis of organic bodies 

 consists in this, that chemistry possesses but a small number of re- 

 actives Ciipable of separating the immediate principles without de- 

 stroying them. iVI. Chevreul, Assistant Chemist in the Museum of 

 Natural History, has endeavoured to render them more useful, hy* 

 employing very different degrees of heat, and thus varying their 

 solvent power. 



For tliis purpose he has contrived a machine, which he calls a 

 diUillatonj digeslsr, consisting in a Papin's digester, shut by a 

 valve attached to a spring. The force of this spring, which is 

 altered at pleasure, determines the degree of heat which th.e liquid 

 must receive in order to escape. The produce of each degree is 

 successively collected by means of a tube passing into a receiver. 

 The solid matter under examination is retained in the digester by 

 means of a diaphragm, by which it may be pressed, and all the 

 remaining liquid forced out of it, 



M. Chevreul has made experiments on cork by this method. 

 He subjected it 20 times to the action of water, and 50 limes to that 

 of alcohol. Having thus separated various substances, there re- 

 mained a cellular body, which he calls subeiin, and which, when 

 treated by i\itric acid, is converted into suberic acid. Among the 

 substances thus extracted from cork, there is one which lie considers 

 as new, and whicli he calls ceri7}, because it possesses several of the 

 properties of wax. 



The some chemist has applied his method to amber, and ascer- 

 tained that succinic acid exists in it in a perfect state. 



He has likewise continued his researches on saponification, of 

 wliich we gave an analysis last year. By comparing fat in its na- 

 tural state with that which has been saponified, he has concluded 

 that the new properties of the last do not proceed from the separa- 

 tion or addition of any constituent, btit from a new mode of com- 

 bination, occasioned by the action of the alkali, which gives to fat 

 an analogy with the acids independent of all oxygenation, 



M. Pelleticr, the son of our deceased associate, has examined the 

 colouring matters from sandal wood and alcanetle [anchvsa tinc- 

 toria), hitherto considered as mere resins. The first, besides pos- 

 sessing most of the properties of resins, is soluble in acetic acid. 



