Chemical Science, 399 



taste. Boiling water dissolves a small portion ; but it is in- 

 soluble in cold water; it is very soluble in alcohol, less so in 

 ether ; it is soluble in acetic acid, and crystallizes from it in fea- 

 thery crystals. Weak sulphuric, nitric, and muriatic acids, do 

 not dissolve or act on it ; the strong acids decompose it. 

 Strong sulphuric acid gives it a blood-red colour, which disap- 

 pears on adding water ; the substance does not seem altered if 

 the acid has not remained long on it. Muriatic acid acts in the 

 same way, producing a deep yellow colour. Nitric acid 

 makes it greenish yellow, orange, and then red ; the ultimate 

 action of the acid produces oxalic acid, and yellow bitter prin- 

 ciple. It melts at about 212°. Destructive distillation con- 

 verts it into water, acetic acid, oil, and carburetted hydrogen, 

 gas: no ammonia is formed. Oxide of copper converts it into 

 carbonic acid and water. After comparing this substance with 

 other vegetable principles, particularly with resins, M. Peiletier 

 concludes by considering it a peculiar substance, and names 

 it Piperin. 



The fatty matter left, after extracting the piperin, is solid, at 

 a temperature near 32° ; but liquefies at a slight heat. It has 

 an extremely bitter and acrid taste; it is very slightly volatile, 

 and tends rather to decompose, than rise in vapour ; that which 

 passes over is not so piquant and acrid, as the undistilled part, 

 but is more balsamic. It dissolves easily in alcohol and ether, 

 and unites to fatty bodies ; and, with the exception of its taste, 

 does not differ from them. From the result of the distillation, 

 it may be considered as composed of two oils : one volatile and 

 balsamic ; the other more fixed, and containing the acridness 

 of the pepper. 



Finally, M. Peiletier finds in pepper — ],Pipirin; 2, a very 

 acrid concrete oil ; 3, a volatile balsamic oil ; 4, a gummy 

 coloured matter ; 5, an extractive principle ; 6, malic and tar- 

 taric acids; 7, starch; 8, bassorine ; 9, lignin ; 10, earthy and 

 alkaline salts. He concludes, also, there is no vegetable alkali 

 in pepper ; that the crystalline substance of pepper is a peculiar 

 body; that pepper owes its taste to an oil but little volatile; and 

 that a strong similarity exists between common pepper and 

 cubebs, as illustrated by the analysis of M. Vanquelin, of the 

 latter compared with the former. — Annates cle Chimie, xvi. p.337. 



21. On Phosphorescence. — The phenomena of phospho- 

 rescence, produced by exposure of bodies to light, have been 

 very attentively observed lately by M. Hcinrich, of llatisbonne, 

 who has made some new and interesting observations on them. 

 The precautions taken by the observer were to remain, previous 

 to the observation, thirty or forty minutes in a perfectly dark 

 place ; to expose the substances, the powers of which were to 

 be observed for not more than ten seconds to the light of a 



