ANTI-MICROBIC SERA 173 



The serum must be fresh and active ; serum heated to 

 56 C. is inert. 



Anaphylaxis, supersensitisation, or hypersensitisation 

 may be of considerable importance in serum treatment. 



On the serum disease, supersensitisation, and anaphylaxis, see 

 Hewlett, Serum Therapy, ed. 2, 1910 ; Rosenau and Anderson, 

 Journ. Amer. Med. Assoc., 1906, p. 1007 ; Von Pirquet and Schick, 

 Die Serum-Krankheit, 1905 ; Richet, Ann. de Vlnst. Pasteur, xxi, 

 p. 497, and Anaphylaxis (Constable and Co., 1913. Bibliog.) ; 

 Besredka, Ann. de Vlnst. Pasteur, xxi, p. 950, and Bull, de Vlnst. 

 Pasteur, vii, 1909, p. 721 ; Currie, Journ. of Hygiene, vol. vii, 1907, 

 pp. 35, 61, and vol. viii, 1908, p. 457 ; Grunbaum, ibid. vol. viii, 

 1908, p. 9 ; Goodall, ibid. vol. vii, 1907, p. 607 ; Bordet, Journ. 

 State Med., 1913, p. 449. 1 



ANTI-MICROBIC SERA. If an animal be injected with 

 increasing doses of bacteria, care being taken to keep 

 below a lethal one, the animal gradually becomes accus- 

 tomed to the microbe, and ultimately acquires a high 

 degree of immunity, so that it is unaffected by amounts 

 which would infallibly kill an untreated animal. More- 

 over, the blood-serum of such a treated animal, if injected 

 into a second animal, will protect the latter against a few 

 lethal doses of the microbe, but not against a large amount. 

 Nor is the protection afforded proportional to the amount 

 of serum injected ; for example, if 0-005 c.c. of anti-cholera 

 serum will protect against 5 mgrm. of living cholera culture, 

 three times as much, or 0-015 c.c. of the serum, will not 

 protect against 15 mgrm. of cholera culture, and when a 

 certain dose of the culture is reached no amount of serum 

 will save the animal. The mode in which the serum acts 

 may be studied microscopically. If cholera anti-serum 

 and cholera culture be injected into the peritoneal cavity 

 of a guinea-pig, and the peritoneal contents be examined 

 at short intervals afterwards, it will be found that the 



1 Trans. XVIIthlntcrnat. Cong, of Medicine, 1913, Sect. IV, Pt. I, pp. 1 

 (Bobi-cdka) and 13 (Richet), and ibid. Pt. II. 



