1906.] 



Antityphoid Serum obtained from the Goat. 



553 



1/20 to 2\ c.c., the dose reached in Goat II when the final test was made 

 only amounted to 1/3 c.c. of juices containing 10 to 12 milligrammes of 

 solid matter. The figures demonstrate the production in considerable 

 amount of an antiendotoxin. The highest titrate obtained was a neutralisa- 

 tion of 30 ascertained lethal doses of endotoxin by 1/50 c.c. of the serum 

 of Goat II. The results confirmed those obtained in the case of Goat I, 

 and were equivalent despite the injection of a much smaller gross amount 

 of typhoid cell juice. The raising of the antiendotoxic value of the serum 

 had likewise been accomplished without any serious disturbance in the 

 health of the animal. This was the difficulty which had retarded the 

 progress of the initial experiments. 



Some tests were made as to the action of the serum on the endotoxin 

 when each was injected separately. The results were as follows : — 



Rabbit I. — Fifteen lethal doses of typhoid cell juice were injected into 

 a vein of the right ear and 1 c.c. serum into a vein of the left ear. A 

 second injection of 1 c.c. serum was given 20 minutes later. The animal 

 survived. 



Rabbit II. — Received five lethal doses of the toxic juice in the right ear 

 and 1 c.c. serum in the left ear. The animal survived. 



Rabbit III. — Received five lethal doses intravenous and f hour later at 

 the onset of toxic systems 2 c.c. of serum. The rabbit survived. The serum t 

 therefore, acted on separate injection into the blood stream. 



The serum of Goat II was also tested against the endotoxin of the cholera 

 organism. One-half cubic centimetre of typhoid serum was added to three 

 lethal doses of cholera cell juice, and the mixture, after incubation for 

 30 minutes at blood heat, was injected into a rabbit. The animal died 

 2\ hours after the injection. One-half cubic centimetre of a typhoid serum, 

 which had been found to protect against 30 lethal doses of typhoid 

 endotoxin, did not protect a rabbit against three doses of cholera endotoxin t 

 and was to this extent specific. The agglutinative power of the serum rose 

 to 1/1,000,000, and 1/10000 c.c. protected the guinea-pig against 10 lethal 

 doses of the typhoid bacillus. 



The serum was finally tested in dilutions of 1/10, 1/100, and 1/500 ac- 

 tor any evidence of a precipitin reaction on the fresh typhoid cell juices. 

 The result was negative. There had been no appreciable development of 

 precipitins in a serum containing at the time, when it was tested, marked 

 antiendotoxic properties. 



