CAPSAICIN

Until the researches of Mr Thresh proved to the contrary the active principle of the capsicum fruit, or cayenne pepper, and the one to which it was thought it owed its acrid and pungent properties, was believed to be an alkaloid, and was named capsicine in consequence. Mr Thresh succeeded in obtaining an alkaloid from the capsicum, but this was entirely wanting in acridity and pungency. Its discoverer states that capsaicin occurs only in the pericarp of the fruit. The details of the proce by which it may be obtained are given in the ‘Year Book of Pharmacy’ for 1876-77, from which it will be seen that the substance may also be procured by preparing a strong tincture of capsicum, and submitting it to dialysis. Capsaicin when cautiously heated to 138° F., melts to a transparent oily fluid, and if then allowed to cool rapidly, it becomes solid, a uming a crystalline condition in doing so. It volatilises at 240° F., without suffering decomposition. Strong nitric acid acts violently on it, decomposing and di olving it. The crystals di olve very readily in ether, amylic, alcohol, acetic ether, benzine, and fixed oils, and still more readily in alcohol, and in rectified and proof spirit. In turpentine and carbon disulphide it di olves much more slowly. It is not affected by boiling for some considerable time in dilute sulphuric acid, and the acid liquor shows no signs of glucose. A specimen of capsaicin which Mr Thresh believes to have been in a pure condition was sent to Dr Flückiger’s laboratory for analysis, and Dr Buri, by whom the combustion was made, reports that it gave the following composition:—C 19 H 14 O 2 , a result which Mr Thresh found to agree very fairly with some capsaicin derived from a specimen fruit obtained from a different source from that sent to Dr Flückiger. Administered internally in doses of the 1 ⁄ 25 th of a gram, capsaicin gave rise to violent griping and purging; and when a lotion consisting of one part diluted with forty of glycerin and spirit was placed on the arm, it soon gave rise to such pain, and caused so much inflammation, that the lint which was wetted with the solution had to be removed very shortly after being applied.