52 



THE TOXICITY OF CAFFEIN. 



TABLE 7. Injection into peritoneal cavity; guinea pigs. 



SERIES A. 



SERIES B. 



SERIES C. 



SERIES D. 



TABLE 8. Caffein by mouth; guinea pigs. 



SERIES J. 



i Subcutaneous injection for comparison. 

 SUMMARY. 



A survey of the results obtained in experiments on guinea pigs shows that the mode 

 of introduction of caffein exerts but little influence on its toxicity. On careful analy- 

 sis it will be observed that the rate of absorption after the administration of caffein by 

 mouth, subcutaneously, or intraperitoneally is about the same for the time of appear- 

 ance of symptoms. The persistence of the symptoms of caffein intoxication observed 

 in these experiments for 24 hours after administration points to slow elimination, 

 which may be expected, owing to the fact that the guinea pigs passed but little urine 

 and caffein is not diuretic for these animals. The prolonged presence of caffein 

 in the body probably exerts a harmful influence or after effect, which may account 



