138 BASIC BODIES. 



No creatine could be found in the substance of the brain, liver, 

 or kidneys. 



Creatine, together with creatinine, was first separated from the 

 urine in the chloride of zinc compound by Heintz* and Petten- 

 koferf although they did not recognise its nature; Heintzf sub- 

 sequently obtained pure creatine from the zinc compound, and 

 employed this substance for his analysis. Liehig, however, showed 

 that the chloride of zinc compound, as yielded by urine, contained 

 for the most part creatinine in chemical combination, the creatine 

 being only mixed with it. 



Origin. When we remember that creatine occurs in the decoc- 

 tion of flesh, and is a highly nitrogenous body, we might be led to 

 regard it as an important nutritive agent, and as taking an active 

 part in progressive metamorphosis. The analogy which, in its 

 chemical relation, and in its constitution, it presents to caffeine, 

 might moreover tend to mislead those who class that substance 

 among nutrient bodies, from its occurrence in certain kinds of 

 food and in certain stimulants. But this analogy is here of very 

 little moment, for we cannot place caffeine among the nutritive 

 agents without giving a very great latitude to the term. A sub- 

 stance, of which a quantity from 2 to 10 grains will produce the 

 most violent excitement of the vascular and nervous systems pal- 

 pitation of the heart, extraordinary frequency, irregularity, and often 

 intermission of the pulse, oppression of the chest, pains in the head, 

 confusion of the senses, singing in the ears, scintillations before 

 the eyes, sleeplessness, erections, and delirium, can scarcely be 

 reckoned among articles of nutrition even by the homoeopath ist, 

 and certainly not by physiologists, when they learn how quickly 

 caffeine becomes decomposed in the organism, and gives rise to an 

 increased secretion of urea. 



The above-named results were yielded by experiments insti- 

 tuted on myself and several of my pupils with pure caffeine. Five 

 persons (one of whom was Professor Buchheim, now at Dorpat), 

 after taking from 5 to 10 grains of this substance, were unfit for 

 any business during the next day, while, in an experiment which I 

 formerly made on myself, 10 grains scarcely produced any percep- 

 tible action. In all the cases there was found to be augmentation 

 of the total amount of urea excreted in twenty-four hours. 



If, however, the analogy between creatine and caffeine does not 



* Pogg. Ann. Bd. 62, S. 602-606. 



t Ann. d. Ch. u. Pharm. Bd. 53, S. 97-100. 



t Pogg. Ann. Bd. 62, S. 602. 



