as ObjeSis of the Art of Dftng^ i^c. 357 



fubftances contain much more oil than vegetable 

 ones, and this oil is foluble in water, which the 

 vegetable oil is not. The animal oil, on diftil- 

 lation yields an alkaline j the vegetable, an acid, 

 liquor. On the different properties of thefe 

 oils, the diftindion between the nature of animal 

 and vegetable fubftances feems chiefly to depend. 

 It is to be remarked, in the analyfis of wool by 

 M. Berthollet, that though animal fubftances 

 yield much volatile alkali on diftillation, no 

 nitrous ammoniac was formed in his procefs; 

 which might have been expeded, had the alkali 

 been previoufly contained in the wool. This 

 facl favours the opinion that the volatile al- 

 kali is formed during the procefs of diftillation. 

 It is at leaft probable that the alkali is fo com- 

 bined in animal bodies, as to require the aid of 

 heat to free it from thofe fubftances, which neu- 

 tralife or conceal it. Or, as we know that there 

 is a ftrong refemblance between volatile alkali 

 and the inflammable principle, may we not fup- 

 pofe that this principle may be forced by heat, 

 into combination with the animal acid, and the 

 alkali be, thus, created* ? Vegetables yield but 



* M. Berthollet has fince proved the volatile alkali to be 

 formed by the union of inflammable with phlogifticated 

 gas ; and that it does not exift in animal fubftances, pre- 

 vious to their diftillation or putrefaftion. The effeAs 

 therefore that have been afcribed to the fuppofed volatile 

 alkali of thefe fubftances, in the procefles of dying, muft 

 depend on fomc other caufe. 



A a 3 little 



