VENOM H^MOLYSIS AND VENOM AGGLUTINATION 197 



cipitate of cell particles and venom granules can be discerned under the 

 microscope. 



Strong solutions of venom are capable of protecting the corpuscles from 

 destruction by water, but venom solutions below 2 per cent in strength render 

 the cells more sensitive to salt solutions, as measured by the toxicity of the 

 fluid for the corpuscles; and as the strength of the venom descends from this 

 limit the susceptibility, as measured by the degree of toxicity, diminishes. 



The next step of inquiry into the mechanism of this phenomenon was 

 taken by Noguchi, who first determined whether the haemolytic amboceptors of 

 venom have any relation to it. The washed corpuscles of horse were mixed 

 with 10 per cent and 2 per cent solutions of cobra venom and acted upon by 

 the latter for two hours. After this period of contact an excess of horse 

 serum or lecithin was introduced into the mixtures. No haemolysis took 

 place in the mixture containing 10 per cent venom, while complete haemolysis 

 occurred in the mixture with 2 per cent venom in it. An activator deviation 

 does not exist here. 



Another way of demonstrating the non-participation of haemolysins in this 

 protective phenomenon was brought out by heating the venom to 95 C. 

 and 100 C. for a brief period. The venom which had been heated to 95 C. 

 was a milky fluid with fine precipitate, but it still had both the protective and 

 haemolytic properties. By separating the coagula by filtration the protective 

 body remains on the filter, while the entire content of haemolysin reappears 

 in the clear filtrate. When the venom is heated to 100 C. for 5 minutes it 

 becomes non-protective, but the heated solution contains the greater portion 

 of the haemolytic principle. Heating to 135 C. destroys both the haemolytic 

 and protective properties in toto. That the haemolytic filtrate of the heated 

 poison exerts a markedly injurious effect on the integrity of washed corpuscles 

 of horse even in a concentration of 10 to 20 per cent of heated venom - 

 is also shown by the reduction of their resistance to toxicity. Until a specially 

 injurious agent, which predisposes corpuscles to laking by physical agents, 

 is discovered in venom, Noguchi is inclined to believe that the injurious action 

 of the filtrate is due to venom haemolysin. 



Another interesting fact was brought out in regard to the venom-protection 

 phenomenon. The serum of rattlesnake is highly agglutinative and haemo- 

 lytic for corpuscles of horse, and yet it does not protect them in any degree 

 against injurious physical agents. The corpuscles of horse, after a contact 

 of 12 hours with the inactivated rattlesnake serum in excess, were haemolyzed 

 by salt solution of 0.45 per cent strength. 



The protection afforded by the strong concentration of venom disappears 

 when the corpuscles are washed in salt solution and freed from the venom. 

 Such corpuscles show a greater diminution of their physical resistance than 

 those treated with a weaker venom solution. It is very singular that the 

 protection is closely associated with the presence of the venom. 



The venomized corpuscles, which are non-haemolyzable even in water, are 

 readily haemolyzed by weak solutions of acid or alkali, and in these cases the 



