234 ^^ i*LASTERS AND SOAPS. 



and thus pro- That this abstraction, rendering the oxigen more abim- 

 priudokr'^''^* dant in the oil, j^ives birth to that saccharine substance, 



which Scheele calls the sweet volatile principle ol' oiLs. 



BifFers from That this sweety principle differs from the raucoso-saccha- 



mucilage and ^.-jp^ ]^^ -^g property of dissolving the yellow oxide of lead : 



that its presence is independant of the presence of oxide; 



and that it differs f-om sugar by its volatility, and by the 



impossibility of brii.ging it to ferm nti 



The oil ac- That the oil, deprived of the elements that give birth to 



proptrUes"of *^^^^ sweet principle, and the quantity of hidrogen and car- 



irolutile oils, bon that constituted it hxed oil, acquires several of the pro* 



perties of volatile oh 

 The only state And finally, that this last state of oil is the only one, in 

 combines with ^^^^'^^ '^ ^^^ combine with white oxide of lead. 

 lead. From the knowledge 1 had' thus acquired of the theory of 



Are plasters this combination of oils, I thought I ishould not neglect to 

 la ic soaps, examine how far the opiaion of several chemists, who con- 

 sidei' plasters as real metallic soaps, is well founded. The 

 analogy between plasters an<l soaps can be confirmed only 

 by observing in their respective combination's a similarity of 

 phenomena, or at least of results. 

 Strong lie -. I mixed very pure soapboilers lie with olive oil, a«d ex* 

 mixed with posed the mi?fture to the air under a glass jar. A week af- 

 ter there was but a very slight absorption ; the sOap had still a 

 strong alkaline taste ; and the oil of tl;is soap did not dis- 

 solve entirely in alcohol. But at the end of six weeks the 

 absorption of oxigen was complete; the soap was very white, 

 and of a good consistence; the taste of alkali in it was 

 faintly perceptible; dilute sulphuric acid extricated from it 

 carbonic acid ; and the oil proceeding from this decomposi- 

 tion had the same consistence as that from plasters, dissolved 

 very readily in alcohol without the assistance of heat, and 

 was precipitated from it by water. 

 Uo sweet prin- ^ made some soap in the same way as soapboilers, and very 

 eiple in water attentively examined the liquor, that remained after the soap 

 soa^p.™^ "^ ^'^^ completely formed; but I could not discover in it any 



trace of the sweet principle. 

 The efF^ct dif- -^^ *^^ absence of this principle in making an alkaline 

 ferent-in de- soap probably depends only on a greater or less abstraction 

 San'iiTkind ^^ Carbon or of hidrogen ; and in other respects thi; action 



of 



