PROTEIN FEVER 397 



solution, when suspended in water, did not give the biuret, 

 but did give an intense Millon reaction, while the part 

 soluble in alcohol gave neither. A duplication of this 

 experiment gave identical results. 



We are not ready to conclude from our work, which has 

 been more extensive than detailed here, that the ferment 

 of the fever serum is strictly specific. An exhaustive meas- 

 urement of its specificity will take much time and close 

 work. The digestive products probably vary much, in 

 amount at least, with conditions, and a close study of 

 parenteral digestion offers a promising field for research. 

 We are inclined to think that the rabbit is a good animal 

 in which to study parenteral digestion, and we suspect 

 that this form of digestion is not altogether abnormal in 

 this animal. We have already shown (p. 355) that egg-white 

 introduced into the stomach or rectum of a rabbit is, in 

 part at least, absorbed unchanged into the blood. Besides, 

 we have observed that our laboratory rabbits when abun- 

 dantly supplied with food often show a rectal temperature 

 of 103 or over, and when the food supply is limited the 

 temperature is lower and more constant. 



The Production of Acute Fever, Followed by Immunity, by 

 Repeated Intra-abdominal Injections of Bacterial Suspensions. 

 In this group of experiments guinea-pigs have been used. 

 The usual method has been to take a standard loop from 

 an agar slant four days old, suspend this in 10 c.c. of normal 

 salt solution, and with a beginning dose of 0.1 c.c. of this 

 suspension, the dose is increased by 0.1 c.c. each time and is 

 repeated every half hour. As a basis for these experiments 

 two guinea-pigs were treated, in the manner described, with 

 the salt solution alone. The result in one of these is shown 

 in Fig. 19. The total range in this case covers 2.7, and it 

 is possible that these injections stimulate parenteral diges- 

 tion slightly. The general agreement of the curve in kind 

 with those to be presented later is quite as interesting, 

 though not so striking as its difference from them in quantity. 

 It is worthy of note that during the continuance of these 

 injections the temperature did not fall below the initial. 



