P IP ERA C EM 173 



and in 1 part of boiling 80 per cent, alcohol ( JFittstein), and 



freely in acetic acid ; tlie last two solutions are precipitated on 

 the addition of water. It is likewise soluble in cbloroform, 

 benzol, and benzin. At 129° C. it melts like wax to a 

 yellowish oily Kquid, which on cooling congeals to a mass 

 of resinous appearance ; when fused it may be ignited, and burns 

 with a bright flame, leaving a light charcoal, which is readily 

 consumed by heating it in the air. Sulphuric acid colours it 

 blood-red, the colour disappearing on the addition of water, 

 leaving the piperine unaltered if the action of the acid has not 

 been prolonged {Pelletier). The solution of piperine in sulphuric 

 acid is yellow, becoming dark-brown, and finally green-brown 

 {Dragendorff) . Nitric acid colours piperine successively greenish- 

 yellow, orange, and redj and dissolves it with a yellow colour, 

 the solution separating yellow floccules on the addition of water ; 

 by prolonging the action of the acid, oxalic acid and a yellow" 

 bitter compound are produced {Pelktier). The resin resulting 

 from this reaction becomes blood-red on the addition, of potassa, 

 and on heating the mixture pipcridine is given off {Anderson, 

 1850). Piperine is a very weak base, and its salts are decom- 

 posed by water ; crystallizable double salts, soluble in alcohol, 

 may be obtained with the chlorides of mercury, platinum, and 

 cadmium. By dry distillation with soda-lime pipcridine is 

 obtained* Boiled with alcoholic solution of pptassa, piperine was 

 found by Babo and Keller (1856) to be resolved into piperic 

 acid, C^^H^^O*, and 2nj)eridine, O'H'^N. Piperic acid is in hair- 

 like, yellowish, needles which fuse at 150° C, and at a higher 

 temperature volatilize partly imaltered, at the same time 

 giving off a coumai*in-likc odour. Pipcridine is a colourless 

 liquid of an ammoniacal and popper-like odour, and when largely 

 diluted of a bitter taste. It boils at 106^ C, has a strong alkaline 

 reaction, dissolves freely in water and alcohol, and yields with 

 acids crystallizable salts ; the piperate of pipcridine crystallizes 

 in silky scales, which^ on being heated, give off a part of the 

 alkaloid. Ladenburg (1884) obtained a small quantity o^ 

 pipcridine synthetically by treating an alcoholic solution of 

 pyridine with sodium. {^National Dispensatory.) Heisch 



