4 i ' Uf^h the Comlination of the fixed Oils 



pt'Ojectcd upon live coals, it burns like the oils : on boiling 

 it with the red, yellow, and white oxides of lead, it only 

 dissolves the yellow one : when distilled several times with 

 the nilric acid, it produces in it the formation of the oxalic 

 acid ; when distilled in a retort in the open fire^ a part 

 ascends in distillation, as observed by Schcele : on increising 

 the fire, it gives cmpyreumatic oil as a result, acetic acid, 

 carbonic acid, carbonated hydrogen gas, and a slight spongy 

 charcoal, which does not contain any oxide of lead. 



From what I have described, it is strongly to be presumed 

 that oil, when combined with the white oxide of lead, is no 

 longer in the same state as it was before this combination. 



In order to separate it from this oxide J made use of the 

 acetic acid, because the solubility of the acetate of lead af- 

 forded me an easy method of separating it from the oil, the 

 properties of which I was about to examine. 



This oil has the consistence of fat, having also the same 

 lancid taste : it is insoluble in water, and soluble in alcohol, 

 and Is precipitated by w^ater in the same way as the volatile 

 oils, and like these last is volatilized in part with the oil in 

 distillation*. 



The slightest ebullition is sufficient for combining it per- 

 fectly with the white oxide of lead, and gives it a strong em- 

 plastic consistence, which does not take place with litharge 

 and massicot. 



The yellow and white oxides of lead cannot he combined 

 with the common oils ; I ascertained this fact by an ebulli- 

 tion much stronger than if I had employed litharge. 



It rejjults, therefore, from these experiments, that when 

 we treat the fat oils with litharge, the oxygen of the latter 

 carries off their carbon, and previously their hydrogen, in 

 order to form water and carbonic acid. 



That this subtraction, rendering oxygen more abundaat 

 in the oils, gives rise to that saccharine s'.ibstance which 

 Schecle calls the sweet volatile principle of oils. 



That this sweet principle differs from the mucoso-saccha- 



* All tlie fat oils are dissolved in alcohol ; those, however, which have 

 been treaty with litharge are much more s,tropgly characterized with this 

 propejty. 



fine 



