374 PROTEIN POISONS 



When a man drinks water containing typhoid bacilli and 

 proves susceptible, he does not immediately manifest symp- 

 toms of this disease. There is a period of incubation which 

 in typhoid fever is about ten days. During this time the 

 bacilli are multiplying in the man's body in great numbers, 

 and are converting his proteins into bacterial proteins. The 

 period of incubation stops and that of the active disease 

 begins when the cells of the man's body become sensitized, 

 elaborate a specific proteolytic ferment, and with this begin 

 to split up the foreign protein. 



The Production of Continued Fever in Rabbits by Repeated 

 Subcutaneous Injections of Dilutions of Egg-white. If the 

 above be true it should be possible to cause a continued 

 fever in animals by repeated injections of a foreign protein 

 in small doses. This was first tried on rabbits with egg- 

 white, and the results are shown in Fig. 12. 



This animal was kept under observation and its tempera- 

 ture taken for six days before the injections were begun. 

 The temperature of this fore period varied from 101.8 to 

 102.5 F. The injections consisted of egg-white with an 

 equal volume of 0.5 per cent, phenol solution, and were 

 freshly prepared each day. The injections w r ere made 

 under the skin over the back and repeated at intervals of 

 two hours from 7 A.M. to 9 P.M. The urine was collected, 

 measured, its specific gravity taken with a picnometer, 

 and its nitrogen content determined by the Kjeldahl method. 

 The animal was weighed once a day. The first injection 

 of 2 c.c. of the egg-\vhite dilution was made at 1 P.M., May 

 27, 1909. This dose was continued at the intervals stated 

 until 3 P.M., June 1, when it was doubled, and. again doubled 

 at 7 A.M., June 4. The animal received 40 doses of 2 c.c. 

 each, 20 doses of 4 c.c. each, and 82 doses of 8 c.c. each of 

 the egg-white dilution; in all 816 c.c. Albumin appeared 

 in the urine when the dose was increased to 4 c.c. The last 

 dose was given at 9 A.M., June 15, after which the albumin 

 in the urine gradually diminished and wholly disappeared 

 June 26. The day before the first dose was given the animal 

 weighed 2525 grams, and on the day of the last dose it 



