86 



ANALYTICAL EXPERIMENTS AND 



Effefts of foda 

 and potafli on 

 benzoin. 



Effe&s of the 

 acids on thefe 

 folutions. 



9. When a boiling lixivium of pure potato is poured on 

 benzoin, a folution is immediately formed; the fame effect is 

 produced when pure foda is made ufeof. Thefe folutions are 

 of a dark brown colour, and become turbid after fome days 

 expofure to the air. 



Precipitates are formed in them by the acids, which are re- 

 diffolved on the application of heat, when nitric or acetic acids 

 Effects of am- are added in excefs. Ammonia likewife diffolves a fmall quan- 

 moniaonben- tity of benzoin, from which folution it is precipitated by the 

 zoin. . 



acids. 



Iffefts of water No alteration is produced when the alcaline folutions are 



on the alcaline largely diluted with water, f 

 folutions. ° J 



§ II. 



ANALYTICAL EXPERIMENTS ON BENZOIN. 



Dijiillation of Benzoin. 

 One hundred grains of very pure benzoin were put into a 

 glafs retort, to which a tubulated receiver, and pneumatic ap- 

 paratus were adapted ; a very gentle heat was firft applied, 

 which was afterwards gradually increafed, till the bottom of 

 the retort became red-hot. The produces thus obtained were 

 as follows. 



Diftillation cf 

 benzoin. 



Component 

 parts of ben- 

 roin. 



Benzoic acid - 



Acidulated water - 



Butyraceous and empyreumatic oil - - 



Brittle coal __-_--. 

 And a mixture of carbonated hydrogen and car- 

 bonic acid gas, which, may be computed at 



Grs. 



9. 



- 5.5 

 GO. 



- 22. 



3.5 



J 00.0 



The quantity of benzoic acid above mentioned is that which 



may be feparated by fublimation only, for on treating the oil, 



(which amounts to 60 grains) with water, five grains more of 



acid may be obtained, fo that 100 grains of benzoin contain 



Oil - - - 55 



Acid - - 14 



* For an account of Mr. Hatchett's experiments on the refins, 

 gum refins, and balfams, fee Thompfon's Syftem of Chemiftry, 2d 

 rdition, Vol. IV. page 305. for the refins and balfams to page 328. 

 And from page 341 to 347 for the gum refins. 



4 The 



