36 ON THE SEBACIC ACID. 



Cr" ft^'hf 8 ^ ^ ebacIc acIt *' u ' hon '*• fol^tion is concentrated and mixed 

 Its peculiar at- w * tn one °* thefe acids, it becomes folid ; finally it does not 

 jraftionsund render turbid the waters of lime, barytes and ftrontites. 

 Thefe properties diilinguith it from all the other acids, and 

 evidently prove that it is an acid J ui generis. 



habitudes. 



B. Means offeparating the Acetous Acid from the Producl of the 



diji illation of Fat. 

 The aqueous fo- THE product of the diftilled fat is treated with water ; the 

 tHled^wn^" liquor is faturafed vvith potafli, and evaporated. When the 

 tains acetous or fubftance is dry, it is introduced into a retort with dilute ful- 



febacic acid, phuric acid, or phofphoric acid, and diftilled : an acid is ob- 

 more largely the r . . * f ' , . . 



greater or lefs tamed, which has all the characters of acetous acid; with 



the heat of dif- potato it forms a foliated fait. This fait is fufceptible of being 

 former is fepa- Opcfcwd by means of heat ; when expofed to the air, it del i- 

 rated by neutra- quefces fpeedily and completely ; its tafte is extremely pim- 

 aft^and'difHi*-" & ent » w ^ a Solution of nitrate of mercury, it forms a preci- 

 ling with ful- pitate cryftallized in the form of fpangles. When fulphuric 

 p unc acid. ac j ( j j s p 0urec j U p on ft, acetous acid is difengaged in abun- 

 dance. Sometimes the water with which the producl: of the 

 diftilled fat has been treated, contains hardly any thing elfe 

 than acetous acid, fo that in order to obtain acetite of potafh, 

 nothing more is necefTary than to evaporate the liquid. The 

 quantity of febacic and of acetous acid formed in the diftilla- 

 tion of fat, varies in proportion to the leifer or greater degree 

 of heat. 



C. Examination of the Odorous Matter, and of the diftilkd Fat . 



The pungent I INTRODUCED fat, which had jufi been diftilled, and 



odour of diftilled ^ f me jj tf whidl was ex t re mely puneent, into a tubulated 



fat is not pro- ■' r r . . 



duced by an retort. I adapted to the neck of the retort, a receiver which 

 acid * contained tincture of Tournefol. Having diftilled with a gen- 



tle heat, I thereby filled the receiver with a flrong odour, and 

 yet the colour of the tincture was not changed — a convincing 

 proof that the fmell of diftilled fat is not owing to an acid ; 

 befides, if this fmell depended upon an acid, it would proba- 

 bly difappear upon placing it in contact with the alkalies, as 

 the acid would then be abforbed ; but this does not happen. 

 We muft therefore conclude, that it depends upon a portion 

 of the fat, converted into gas, and undoubtedly changed in its 

 nature. 



» D. Examination 



