146 CHEMISTRY OF IMMUNITY AGAINST BACTERIA 



attacks the bacterial protoplasm. It may degenerate and lose 

 its toxophore group while retaining the power to combine by- 

 means of its haptophore group, thus forming a complementoid. 

 Complement and amboceptor exist side by side in the serum, 

 not uniting with one another until the amboceptor has become 

 attached to the bacterial protoplasm. 



In its effect of dissolving bacteria (and also other cells against 

 which animals may have been immunized) complement resembles 

 the enzymes, and it is generally looked upon as related to them. 1 

 As yet, however, none of the products of proteolysis has been 

 isolated from substances acted upon by complement, nor do the 

 changes it produces resemble those produced by proteolytic 

 enzymes in all details. In particular, complement seems to 

 participate in reactions according to the law of definite propor- 

 tions, unlike the enzymes. 2 The chemical nature of comple- 

 ment seems to be entirely unknown. In certain immune reac- 

 tions, colloids (lecithin, silicic acid 3 ) can play the role of com- 

 plement and immune body, but these reactions are probably 

 quite different from those of bacteriolysis by immune serum. 



Immune body (amboceptor) is formed, according to Wasser- 

 mann, and Pfeiffer and Marx, in the spleen and hemopoietic 

 organs, since in immunization it can be demonstrated in these 

 organs before it appears in the circulating blood. The resistance 

 of immune bodies is very considerable : serum prepared in 1895 

 by Pfeiffer against cholera vibrios was found to have lost almost 

 none of its activity after eight years in an ice-box (Friedberger). 

 Heating twenty hours at 60 scarcely injures them, but 70 for 

 one hour destroys them almost completely, and heating the serum 

 to 100 destroys all the immune bodies. They are quite resistant 

 to putrefaction, and, like the antitoxins, do not dialyze. 



According to Pfeiffer and Proskauer, 4 digestion of the glob- 

 ulin precipitate, in which immune bodies are carried down, 

 does not destroy their activity completely even when all the 

 proteids are thus removed. Removal of the nucleo-albumin or 



1 The suggestion has been made that bacteriolysis, even in immune serum, 

 depends upon osmotic disturbances. Lootz and Tallant (Johns Hopkins Hosp. 

 Bull., 1900 (11), 220) tested the electrical conductivity of the serum before 

 and after heating to 57, and found no change, speaking strongly against this 

 rather poorly based hypothesis. Leuchs (Arch. f. Hyg., 1905 (54), 396) also 

 failed to find evidence that bacteriolysis by immune serum is due to osmotic 

 changes. As regards the resemblance of bacteriolysis to proteolysis, see Turro, 

 Berl. klin. Woch., 1903 (40), 821. 



2 See Liebermann, Deut. med. Woch., 1906 (32), 249. 



3 Landsteiner and Jagic, Wien. klin. Woch., 1904 (17), 63 ; Munch, med. 

 Woch., 1904 (51), 1185. 



4 Cent. f. Bakt,, 1896 (19), 191. 



