g3 ANALYTICAL EXPERIMENTS AND 



which is precipitated by the diluted fulphuric acid. The fol- 

 lowing table (hews the quantity of benzoic acid, obtained by 

 the different procefles, from one pound of benzoin. 



Oz. Dr. Scr. Grs. 

 Scheele's procefs - - - - 1 6 2 19 



Chaptal's - - - - - 2 



By boiling benzoin with water - - 1 10 

 By Gren's and Gottling's procefles - 15 110* 

 The acid of Benzoic acid is defcribed by Blaife de Vigenere, as long agd 



b.nicin, firft as the year 1608, in his treatife on fire and fait; he called it 

 Btafede y flowers of benzoin, becaufe it was obtained by fublimation. 

 Vigenere. We are indebted to Tromfdorf and Lichtenftein for many fads 



relating to this acid. 



Properties of the Acid of Benzoin. 



This acid when obtained according to Scheele's procefs, is 

 Tafte of die a l'^ lt yeUowifh powder. Its taile is hot and rather bitter. 

 acid. It poflefles a fomewhat fragrant fmell, arifing from a fmall por- 



tion of the aromatic oil, which ftill adheres to it, it has how- 

 ever been obtained without any fmell by Giefe. 

 Properties in It reddens tincture of turnfole. Jt is volatilized by a gentle 



genera). heat, being converted into a white fmoke, which excites a 



very difagreeable fenfation in the throat. When melted, it 

 becomes as fluid as water, and aflumes a radiated furface on 

 cooling. Its (peci/ic gravity is 0.667. 

 Dccompofition. When diftilled in clofe veffels, a part of it is decompofed, 

 which is converted into oil and carbureted hidrogen gas. — 

 Effect of oxigen Tromfdorf f found that it was not altered by oxigen gas, nor 



by the fimple combuftibles or incombufiibles. 



gas, &c. on thi 

 acid. 



Of fulphuric It is foluble in fulphuric acid, which it converts into a brown 



liquid, and from which it is feparated by the addition of water. 

 Of nitric and The fame effects are produced by nitric acid, and by fulphu- 

 fulphurous and re0lls anf j nitrous acids. It is not acted upon by muriatic, ox- 

 Iffefts of mu- ymuriatic, or phofphoric acids. It is eafily foluble in alcohol, 

 rutic acid, Sec. [ Tom ^vhich it is precipitated on the addition of water. Its 



* Of pure acid, obtained by treating the precipitate with boiling 

 water. 



t See Tromfdorf 's experiments on the benzoic acid, in his Journal 

 sLr Pharmacie. 



affinities 



