INTERACTIONS BETWEEN VENOM AND ANTIVENIN 249 



acidified mixture, does not combine with the antivenin produced with native 

 venom; therefore, Morgenroth has succeeded in regaining the antivenin out 

 of the mixture of venom and antivenin once completely neutral. 



Calmette and Massol* next studied the question of the regeneration of venom 

 from the neutral venom-antivenin mixture, not only by the method of Mor- 

 genroth, but also by using alcohols. Their investigations on this subject are 

 very instructive and throw much light on the nature of the interaction of 

 venom and antivenin. The principal facts obtained by them may be briefly 

 summarized in the following: 



(i) The atoxic compound of cobra venom and its antivenin has entirely 

 different properties from those of its components. 



(2) The toxic substance of cobra venom is soluble in liquids containing 

 50 to 80 per cent alcohol. On the other hand, in the presence of antivenin, 

 the venom begins to become insoluble in 50 per cent alcohol and is almost 

 completely insoluble in 64 per cent. The antivenin by itself is insoluble in 

 alcohol, and after a short time of contact is destroyed by this reagent. 



(3) The antivenin, in the presence of venom, ceases to be destroyed by 

 ethyl alcohol, even in 80 per cent concentration, and remains active in the 

 presence of this reagent. The same holds good for other precipitants, such 

 as methyl alcohol, propylic alcohol, acetic ether, and acetone. The sulphates 

 of ammonia and magnesium precipitate the venom-antivenin compound 

 without dissociating the two. 



(4) The toxic substance of cobra venom is not coagulated by heating it 

 to 76° to 80° C. 



(5) The antivenin is destroyed by the temperature of 68° C. But when 

 mixed with venom it becomes thermostabile up to 75° C. At this tempera- 

 ture (at least the serum which they studied) the atoxic compound of venom 

 plus antivenin is partially dissociated, and the venom accordingly goes in solu- 

 tion. That which remains in combination is insoluble. This phenomenon 

 occurs as well at 80° C. 



(6) In the presence of the majority of the mineral or organic acids (of 

 which sulphuric, formic, oxahc, acetic, butyric, succinic, tartaric, citric, maleic, 

 lactic, and boric acids have been tested), and under the influence of the 

 temperature of 72° C, the antivenin composing the atoxic compound venom 

 and antivenin regains its thermolabihty and the venom is set free. The 

 venom is not destroyed by antivenin and it can be recovered almost com- 

 pletely by this treatment. Boric, succinic, and butyric acids are ineffective. 



(7) In the presence of 50 per cent ethyl alcohol and free mineral or organic 

 acids, the atoxic compound of venom and antivenin can be dissociated at the 

 laboratory temperature. The antivenin, after 10 to 15 minutes, is so little 

 modified that, at least in part, it can reconstitute the original atoxic com- 

 pound of venom and antivenin. The venom is not destroyed by the anti- 

 venin and one can recover it almost all quantitatively. Thus the atoxic 



1 Calmette and Massol. Relations entre le venin de cobra et son antitoxine. Ann. Inst. Pasteur, 

 1907, XXI, 929. 



