ACUTE INTOXICATION GUINEA PIGS. 



51 



these animals was very scanty, as shown in the preceding record of the experiments; 

 this means slow elimination of caffein and its products of decomposition. It is con- 

 ceivable that the presence of toxic amounts of caffein in the body for a considerable 

 length of time would induce changes that ultimately lead to the death of the animal 

 or that morbid processes are set up by the combined action of caffein and some pre- 

 existing poison. Since some guinea pigs, however, survived the doses indicated, it 

 is more probable that such changes would be brought about by caffein in the presence 

 of a preexisting poison. The death of these pigs, and also of No. 137 several days later, 

 is difficult to account for on any other theory than the one suggested. Were it not for 

 the fact that controls, that is, animals of the same lot which had not received caffein 

 survived all of the experimental animals, changed conditions of environment or acci- 

 dent might be considered the cause of death in the guinea pigs of the last series. 



TABLE 6. Subcutaneous injection of guinea pigs. 



SERIES A. 



SERIES B. 



SERIES C. 



SERIES D. 



SERIES E. 



