158 . APPENDIX. 



petroleum method gfves very good results, about O'lO per cent., and 

 would probably be preferred on the score of expense. Comparative 

 experiments made on the young and old leaves freed from the stalks 

 show that the old leaves afford when dried 0*072 per cent, of the 

 alkaloid, the young leaves 0'25 per cent., and that on an average a 

 papaw plant can be calculated to affoi'd 30 grams of the alkaloid per 

 year fi'om the leaves. The hydrochlorate of cai*paine, which contains 

 about 82 per cent, of the pure alkaloid, is freely soluble in water. As 

 yet comparatively little is known of the physiologiiial action of the 

 alkaloid. It appears, however, to act more especially upon the heart, 

 ^lowing its action. The lethal dose for a fowl of 500 gi'ams weight 

 was found to be about 200 milligrams. In a fowl of 350 grams 



m 



weight no poisonous symptoms were pi'oduced with 50 milligrams of 

 the alkaloid ; with 100 milligrams symptoms of poisoning occurred in 

 ten minutes after injection into the breast muscles, but after twenty- 

 five minutes the animal recovered its normal condition. The bird 

 lay on its side and breathed deeply in a jerky manner, and showed 

 slight couvalsive movement of the whole body, but no irritability 

 was noticed. Farther observations are necessary to determine the 

 usefulness or otherwise of the alkaloid in medicine ; should it prove 

 of utility, there can be no difficulty in obtaining it in almost 

 unlimited quantity and in a definite crystalHao condition. The 

 alkaloid is easily precipitated from its solutions by the alkaloid 

 reagents. The most delicate reaction is with Mayer's reagent, 

 iodoiodide of potassium, which in a solution of 1 in 300,000 gives 

 a turbidity, and in 80,000 parts an evident precipitate ; phosphomolyb- 

 date of ammonium has its limit of reaction at 1 in 75,000 parts, 

 picric acid at 1 in 30,000, and chloride of gold at 1 in 25,000. 

 The alkaloid has a bitter taste, which is perceptible even in a solu- 

 tion of 1 part in 100,000. 



CUCURBIT ACE^ . 

 Constituents of Melon Seeds. 



C. Forti (Chem. Centr., 1890, ii., 581) found these seeds to contuiu 

 cholesterin and a dextro-rotatory carbo-hydrate apparently belong- 

 ing to the galactan group. 



The oil yielded by tlie seeds to ether amounts to 49 per cent., and is 

 almost free from fatty acids. It contains lecithin. The phosplioinis 

 amounts to about 0'02 per cent. (Year-Booh of Phann. 1801, p- 104.) 



