Chemical Science. 197 



is a substance not volatile, not pre-existing in the seed, and which 

 may be due to sinapisine, combined with some other product ; for 

 when once the latter is separated, the former is not produced. 

 Both contain sulphur, iii. The active principle of black pepper is a 

 volatile oil, having no pre-existence, and not capable of develop- 

 ment without the contact of water, iv. There is probably a principle 

 in this seed from whence the sulphur found in the volatile oil is 

 derived, v. Sinapisine, extracted by alcohol, without the intervening 

 action of water, has not the property of reddening the persalts 

 of iron, nor of evolving odour by the action of caustic alkalies. It 

 is less soluble in alcohol, and contains less nitrogen than the sulpho- 

 sinapisine of M. Henry and Garot, but it contains sulphur essentially* 

 In the same Number is a memoir by M. Faure on the same 

 subject, in which he also shows the important part performed by 

 water, in contributing to the formation of those substances which 

 characterise black pepper, and make it valuable in medicine. In 

 every pharmaceutial preparation into which mustard powder enters, 

 lie considers it essential that as much taste and odour should be de- 

 veloped as possible, and that the powder should first be mingled with 

 water, and then the other substances added. Acids and alkalies do 

 not add to its irritating effects, except perhaps by those which they 

 themselves possess. He arrives at the following chemical conclu- 

 sions : i. The volatile oil of mustard does not pre-exist in the seeds 

 or powder; water is indispensable to its formation, ii. Besides the 

 well known principles in black mustard, it appears to contain a par- 

 ticular green substance, which appears to aid in forming the volatile 

 oil. iii. Sulpho-sinapisine is one of the principles of black mustard, 

 and accompanies the green matter in almost every operation to which 

 the seed is subject, iv. Ether has no marked action on the consti- 

 tuent elements of the volatile oil. v. Rectified alcohol, and weak 

 acids and alkalies, when added to mustard powder, oppose the for- 

 mation of the volatile oil. 



22. SALICINE. 



MM. Herberger and Buchner have found salicine to be a sub-salt, 

 containing a true vegeto-alkali. The salicia, or base, has all the 

 properties of those bodies, except that it dissolves with facility 

 in water. When burnt it left no residue. It differs from salicine 

 by its alkaline action on litmus paper ; by its crystals, which are ne- 

 vertheless prismatic; by its solubility in water, and by its action 

 on concentrated and dilute acid. It is not so soluble in alcohol as 

 salicine. The sulphate, nitrate, phosphate, acetate, tartrate, oxalate, 

 and muriate of salicia, have been made ; ether does not dissolve them, 

 alcohol does, and upon evaporation leaves them (if there be not 

 enough water of crystallization) in a pulverulent or flocculent form. 

 When heated the salts fuse ; then become dry ; and when more 

 highly heated, fuse and are decomposed with the odour of quinia in 



* Journal de Pharmacie, 1831, \\ 299. 



