Chemical Science. 631 



solutions, from the latter of which it is precipitated by acids. Acetic 

 acid dissolves it nearly in the same proportion as boiling alcohol ; 

 the solution is intolerably bitter and yields regular crystals. By 

 nitric, sulphuric, and muriatic acids, as well as by intense heat, it is 

 decomposed, without any evolution of ammonia. The solutions in 

 alcohol and acetic acid are not changed by the tincture of galls, 

 nitrate of silver, acetate of lead, or any other metallic salt. 



It is very probable that the astringent property of columbo re- 

 sides in the substance in question ; and as the method of preparing 

 it is so very simple, it would perhaps be worth while to try its 

 medicinal effects *. 



22. ON THE COMPOSITION OP CAMPHOR AND CAMPHORIC ACID. 

 (By J. Liebig.) 



The researches of MM. Brandes (Schweigger's Journal, s. 38, 

 269,) and Bouillon Lagrange, (Ann. de Chim., t. xxiii. and xxvii.) 

 on camphoric acid, have led to very different results ; for, according 

 to the latter chemist, the camphorates of potash, soda, and baryta, 

 are almost insoluble in water, whilst the former found them very 

 soluble and almost deliquescent in the open air. This and other 

 differences are, however, only apparent, and, as will be seen, may be 

 accounted for by the different kinds of camphoric acid which were 

 examined by these two chemists. It is sufficiently known that cam- 

 phor, when digested with strong nitric acid of s. g. 1.425, dissolves into 

 yellowish liquid, which, on continuing the digestion gradually disap- 

 pears ; the solution, when left to cool, deposits, a great quantity of 

 white non- transparent crystals, which, when boiled with water, com- 

 municate to its vapours a smell of camphor. This crystallised sub- 

 stance is Bouillon's camphoric acid; its salts are very insoluble, 

 and it consists of a mixture of camphor and camphoric acid, as may 

 be ascertained by dissolving the former in the latter substance by a 

 gentle heat. If the crystals are again submitted to the action of 

 nitric acid, transparent crystals of camphoric acid are obtained, the 

 compounds of which with bases correspond with the camphoratea 

 described by Brandes. This acid I considered as pure, although, on 

 boiling it with water, it communicated to the vapours a camphoric 

 smell. In order to ascertain its atomic weight, the camphorate of 

 lead was decomposed by sulphuric acid, and it was found that 



0.785 of camphorate of lead yielded 0.527 of the sulphate, and 

 1.129 . . . 0.772 



so that the equivalent of camphoric acid would be 140.34; it does 

 not contain any water of crystallisation. The proportion of its 

 elements was determined by burning crystallised camphoric acid 



* Poggendorff a Annal. 1830, p. 298. 



2 T 2 



