on Cinnamic Acid and on Salicine. 39 



The slight excess in the carbon is probably owing to a 

 little of the cinnamic acid having escaped decomposition. 



Peroxide of lead is therefore a more elegant test for cin- 

 namic acid than nitric acid, as there are no fumes, as is the 

 case when nitric acid is employed to disguise the smell of oil 

 of bitter almonds, the taste of which is easily perceptible in 

 the liquid. 



Hypochlorite of lime also converts cinnamic acid into ben- 

 zoic, but the oily liquid which is then formed is not oil of 

 bitter almonds, as its taste and smell are quite different, and 

 much more aromatic. The extremely small quantity in which 

 it was obtained, however, unfortunately prevented me from 

 being able to subject it to examination. The cinnamic acid 

 on which I operated, was obtained by boiling balsam of Peru 

 with a solution of potash, which is the most ceconomical pro- 

 cess for cinnamic acid. 



Action of Peroxide of Lead on Salicine. 



When a solution of salicine was boiled with a quantity of 

 peroxide of lead, the peroxide of lead gradually assumed a 

 light brown colour. The whole was then thrown upon a 

 filter, and the clear liquid which passed through had a bitter, 

 and at the same time a sweetish taste, which reminded one at 

 once of that of salicine and of the soluble salts of lead. A portion 

 of. the liquid was introduced into a retort, and a little sul- 

 phuric acid was added. This occasioned a copious precipi- 

 tate of sulphate of lead, and the red coloured substance called 

 rutiline, which is always produced when sulphuric acid acts 

 upon salicine, also made its appearance. On applying a gentle 

 heat the liquid which passed into the receiver was strongly 

 acid, and when heated with a few drops of nitrate of silver, 

 the oxide of silver was reduced to the metallic state, clearly 

 indicating the presence of formic acid. The other portion 

 of the liquid, on standing some time, became muddy, and de- 

 posited a small quantity of a flocculent precipitate. On add- 

 ing a few drops of ammonia, however, a very bulky preci- 

 pitate fell, which was soluble in acetic acid and in solution of 

 potash. It consisted of the combination of lead and salicine 

 discovered and analysed by Piria. On treating it with a cur- 

 rent of sulphuretted hydrogen till all the lead was precipi- 

 tated, and purifying the salicine thus set free by two or three 

 crystallizations, I found that the salicine had undergone no 

 alteration. On being subjected to analysis, 

 gramme. 



i. 0*32*7 substance gave 0*65 carbonic acid, and 0*1865 

 water. 



