494 Journal of Agricultural Research voi. xiii, no. io 



tein splitting and then comparing it with the loss in potency of the 

 serum. The results obtained after 1 1 inoculation experiments, in which 

 371 guinea pigs were used, were inconclusive. The digested anthrax 

 serum apparently immunized guinea pigs against anthrax virus as often 

 as it did not. Repeated attempts to obtain definite results were un- 

 successful. The main reason for this probably lies in the fact that there 

 is no known quantitative relation between anthrax serum and virus 

 such as there is between tetanus and diphtheria antitoxin and toxin. 

 Unlike the unorganized tetanus and diphtheria toxins, which can not 

 grow or multiply when injected into a test animal, a most carefully 

 standardized dose of anthrax virus, containing a definite number of 

 organisms, can grow to an extent which varies with the resistance of 

 the animal. 



SUMMARY 



(i) Tetanus antitoxin in 0.5 per cent sodium-carbonate solution was 

 slowly and completely destroyed. At the same time no significant 

 chemical changes in the proteins were detected. 



(2) In solutions amphoteric or faintly acid to litmus-paper strips, 

 trypsin destroys the antitoxin, and at the same time the as- 

 sociated proteins are digested. The rates of antitoxin destruction and 

 protein splitting were substantially the same. 



(3) The results were the same with solutions containing trypsin and 

 0.5 per cent sodium carbonate. 



(4) Tetanus antitoxin in 0.2 per cent hydrochloric acid was completely 

 destroyed in three or more days. During this time no significant chem- 

 ical changes in the proteins were detected. 



(5) In neutral solutions pepsin did not aflfect the antitoxin. 



(6) In pepsin-hydrochloric acid, proteolysis and antitoxin destruc- 

 tion proceed simultaneously. 



(7) These results tend to indicate that tetanus antitoxin is a sub- 

 stance of nonprotein nature. But the stability of the antitoxin is so 

 dependent upon that of the protein to which it is attached, that when- 

 ever the protein molecule is split, the antitoxin splits with it. 



LITERATURE CITED 

 (i) BanzhaF, E. J., SuGUiRA, K., and Falk, K. G. 



1915. STUDIES ON ANTI BODIES. I. ANALYSES AND NITROGEN DISTRIBUTION 



OF A NUMBER OF ANTISERA. In Collect. Stud. Bur. Labs. New York, 

 V. 8, p. 213-222. 



(2) Belpanti, S., and Carbone, T. 



1898. CONTRIBUTO AiLA CONOSCENZA DELL* ANTlTOSSINA DIFTERICA. In Atch. 



Sci. Med., v. 22, no. 2, p. 9-35. 



(3) BERG, W. N. 



1916. biochemical COMPARISONS BETWEEN MATURE BEEF AND IMMATURE 



VEAL. In Jour. Agr. Research, v. 5, no. 15, p. 667-711,6 fig. Litera- 

 ture cited, p. 70&-711. 



