58 ANAPHYLAXIS AND ANTI-ANAPHYLAXIS 



— at I2.IO a.m. 0-05 c.c. serum intraperitoneally, at 

 1.30 p.m. 5 c.c. by the same route, at 3.30 p.m. 

 o-i c.c. injected into the jugular vein, at 3.35 p.m. 

 0-5 c.c. again by the jugular vein, at 3-45 p.m. a final 

 injection of 5 c.c. into the vein. By this method an 

 animal for which 0-025 <^-c- would have been in excess 

 of the lethal dose is able to tolerate, after four gradu- 

 ated injections in less than four hours, 5 c.c. of serum 

 inoculated intravenously — that is, more than 200 

 times the lethal dose given in one injection — without 

 any symptoms of anaphylaxis. 



We give also other examples taken at random 

 from our notebook of experiments. On October 10, 

 1 9 10, a series of guinea-pigs was actively sensitised 

 with egg-albumen. On October 28 one of the animals 

 was inoculated with o-oi c.c. by the jugular route. 

 It was seized at once with anaphylactic symptoms 

 and died in two minutes. Another animal of the 

 same series was similar^ injected with 0-002 c.c. egg- 

 albumen. One minute after the injection it was 

 hkewise seized with anaphylactic symptoms and died 

 within four minutes. The lethal dose was therefore 

 0-002 c.c. This fact having been ascertained with 

 certainty, we gave a third guinea-pig of this series 

 graduated injections of egg-albumen, beginning with 

 0-0005 c.c, by the jugular route. There was no 

 reaction. Two minutes later we injected it with 

 0-002 c.c. — that is to say, an absolutely lethal dose. 

 It did not react. Ten minutes afterwards it was 

 given 0-02 c.c. without reaction. Again, ten minutes 

 later, we injected its jugular vein on the opposite side 

 with 0-2 c.c. without reaction. After another interval 

 of ten minutes, we injected it with 2 c.c. of undiluted 

 egg-albumen. The animal was obviously embarrassed 

 by the injection, but it recovered immediately. 



A sensitised guinea-pig, therefore, which has been 

 given four graduated inoculations in the space of 



