june3, igis Destructtofi of Tetauus Antitoxtti 483 



to have an appreciable influence. The determinations of coagulable 

 protein and amino nitrogen in trypsin mixtures were made within a 

 day or two of one another, but in the peptic mixtures a longer interval 

 was regarded as permissible on account of the much slower liberation 

 of amino nitrogen. The results are tabulated below. The amounts of 

 amino nitrogen per gram of coagulable protein are practically the same 

 in tetanus serum, anthrax serum, and ordinary beef and veal muscle 

 tissue. 



Milligrams of amino nitrogen per gram of coagulable protein 



Tetanus antitoxin, 420 F 1 17. 4 



Tetanus serum, 374 i^^. 2 



Tetanus serum, 268 120. 8 



Average of 3 123. 8 



Tetanus antitoxin X « 123. 8 



Anthrax serum, 48 no. 3 



Anthrax serum 48.3 120. 2 



Average of 5 120. 4 



Normal beef or veal muscle tissue {Berg, j, p. 680). On the basis of 16 percent 



of nitrogen in protein 1 16. 8 



Above tissue freed from extractives 120. o 



Banzhaf, Sugiura, and Falk (/) made analyses and determined the 

 nitrogen distribution of a number of antiserums, but found no marked 

 differences in the compositions of the proteins in normal serum, tetanus, 

 and diphtheria globulins, etc. The above figures are in accord with the 

 findings of these investigators. All indicate that the normal serum 

 proteins, as they pass over into immune serum proteins, do not undergo 

 chemical changes that are detectable by present methods. The same is 

 probably true of tissue proteins. 



To calculate the percentage of the total amino nitrogen liberated by 

 digestion, in experiment 22, for example, from the analytic data in 

 Table III, i c. c. of serum 268 in mixture D contained 2.73 mgm. of amino 

 nitrogen after 5 days' digestion; at the same time a similar quantity of 

 serum in mixture A, in which no digestion was taking place, contained 

 0.56 mgm. Therefore, in mixture D, 2.73-0.56 = 2.17 mgm. of amino 

 nitrogen were liberated by the digestion for each cubic centimeter of 

 serum. If all of the amino nitrogen were thus liberated, 11.78 mgm. 

 would be present; hence, 2.17/11.78 =-18 per cent of the total was liber- 

 ated by digestion. This figure, 18 per cent, together with other figures 

 similarly calculated, is to be found in Table VII. 



INOCULATION TESTS 



The amounts of antitoxin remaining in the various mixtures were 

 determined, after suitable digestion periods, according to the method 

 described by Rosenau and Anderson (zj). 



a For antitoxin X, a lack of material for analysis necessitated the assumption of the above average. 



