186 VENOMOUS SNAKES AND THE PHENOMENA OF THEIR VENOMS 



tion, there is always some reduction in this power. But if the neutralized 

 venom solution be left in the room temperature for a few days and its haemo- 

 lytic strength be again measured, it will be found that the venom solution had 

 become once again as strongly haemolytic as its original native venom solution. 

 On the other hand, the haemolytic power of cobra venom heated without HC1 

 remains at its reduced value without regaining its lost strength during the same 

 length of time. Even after a lapse of only 4 hours the return of the haemolytic 

 strength was often seen to be very complete. 



Faust * tested his ophiotoxin for the haemolytic property and found that this 

 substance has quite marked action upon the washed or unwashed corpuscles 

 of ox, pig, horse, and sheep. Heating to 90 C. for 15 minutes did not destroy 

 its haemolytic power. 



Ishizaka 2 studied the haematoxic action of the venom of Lachesis flavo- 

 viridis and found that the blood of dog is more susceptible to the haemolytic 

 action than that of cat, rabbit, ox, or rat. 0.05 c.c. of dog's blood promptly 

 dissolved by 0.000002 gm. of the venom, while 0.0000002 gm. caused only 

 a trace of lysis. Cat's blood is much agglutinated, but only slightly dis- 

 solved even in a comparatively large quantity of the venom, while 20 mg. of 

 the same failed to haemolyze any part of the blood of mouse, ox, or rabbit. 

 In these cases more or less agglutination took place. In support of the obser- 

 vations of Flexner and Noguchi, he found with this venom that thorough 

 washing of the corpuscles retards or diminishes haemolysis to a great extent. 

 With the most susceptible kind of blood, namely, that of dog, Ishizaka 

 found that after 3 to 6 washings the corpuscles become completely insus- 

 ceptible to the smaller quantities of the venom. He found that lecithin 

 can activate this venom very easily. Cholesterin is found to inhibit haemolysis 

 caused by the habu venom, but not by combining directly with the latter; this 

 latter fact has been shown by Noguchi in his former studies. 



In 1907 Noguchi attempted once more to clear up the questions concerning 

 the susceptibility of the corpuscles of certain kinds of bloods and the non- 

 susceptibility of those of some other kinds to the haemolytic action of venom. 

 It appeared to him still quite uncertain why one set of the blood serums is 

 able to activate venom, while the other is not. As to the nature of the thermo- 

 stabile venom activators of the blood serum, Noguchi agrees with Kyes that it 

 is chiefly lecithin which is capable of venom activation. But some serum 

 contains, besides lecithin, certain thermolabile activators, whose action dis- 

 appears when heated to 56° C. for half an hour. There are numerous serums 

 which are devoid of venom-activating property in the fresh state, but these 

 all become invariably activating when heated to the temperature near or 

 above the coagulation point. In these instances there is no doubt that leci- 

 thin is liberated by heat and activates venom freely. This, however, does 

 not explain the venom-activating property of the fresh serums; it only sug- 

 gests that lecithin may exist in one set of serums in a state to be acted upon 



1 Faust. Ueber das Ophiotoxin aus dem Gift der ostindischen Brillenschlange. Leipzig, 1907, 19. 



2 Ishizaka. Studien iiber das Habuschlangengift. Zeitschr. f . experim. Pathol, u. Therapie, 1907, IV, 



88. 



