176 



Messrs. E. C. Hort and W. J. Penfold. [Feb. 17, 



experiment already reported by one of us this injection ratio is stated. In 

 all experiments here cited the same rule is observed. In our experiments 

 we found it necessary to select animals as far as possible of the same age 

 and weight, and to observe constant conditions of food supply and external 

 temperature. All thermometric observations were taken in the rectum 

 every 30 minutes, instruments of tested accuracy being always employed. 

 Every observation has been taken by us, and never entrusted to assistants. 

 The upper normal limit of the daily range of temperature in 150 healthy 

 rabbits was found to be 103-2° F. All animals with a temperature more 

 than slightly above this point were rejected, as well as those showing any 

 apparent departure from health in other ways. Animals less than 

 1500 grm., or more than 3000 grm., in weight are unsuitable for experiment 

 if the rabbit be used, the former weight indicating too unstable a tem- 

 perature, the latter too resistant. Eeference is here made only to early 

 fever occurring within five hours of injection, and statements as to the 



23 456789 



A. Eabbit, 2448 grm., injected intravenously with 11-50 c.c. water containing F.P.B. 



Injection ratio, 1/211. 



B. Eabbit, 2478 grm., injected intravenously with ll - 80 c.c. water containing no F.P.B. 



Injection ratio, 1/211. 



(Interval between observations, 30 minutes.) 

 X corresponds to upper normal limit of range of temperature in healthy rabbits. This 

 letter occurs throughout the charts. 



