3 1 4 IMMUNO-CATALYSIS 



failure occurs and the heart ceases to beat in diastole or in midposition. 

 Extracts of normal monkey's liver, which by themselves have no action, 

 protect from the action of 'lysocithin/ and if the protection is not com- 

 plete a gradual failure occurs similar to that caused by envenomed 

 liver'; cobra venom (2-4 mg.) causes rapid failure and systolic con- 

 traction of the heart. 



"7. Injected into the anterior chamber of the rabbit's eye, en- 

 venomed liver,' 'lysocithin,' and cobra venom cause opacity of the 

 cornea and irregular alterations of its curvature. Extracts of normal 

 monkey's liver are wdthout effect. 



"8. Injected intravenously into guinea pigs, envenomed liver' and 

 'lysocithin' cause symptoms resembling acute anaphylactic shock with 

 the addition of haemorrhagic oedema of the lungs. 



"9. Washed sheep's red corpuscles are immediately haemolyzed by 

 'envenomed liver' and 'lysocithin' but not by cobra venom* nor by 

 extract of normal monkey's liver; the latter has a protective action 

 against haemolysis by 'lysocithin.' 



"10. 'Envenomed liver' and 'lysocithin' injected into the perfused 

 dog's liver cause output of protein, histamine and pigments; with 

 repeated injections the output of histamine increases. These effects 

 are closely similar to those produced by repeated injections of small 

 doses of cobra venom." 



In addition to the protection, or neutralization, provided by anti- 

 venom serum against the toxic effects of clotting and proteolytic en- 

 zymes, and lecithinases of snake venom, antivenom neutralizes also 

 the nucleic acid hydrolyzing enzyme or enzymes present in the venom. 



2. Ricin 



a. Chemical Nature of Ricin. Similar to snake poisons and bacterial 

 toxins there are a number of plant poisons which are either strongly 

 hemolytic or exercise hemagglutinating activity. They are ricin, abrin, 

 crotin, curcin, robin, etc. Of these crotin and curcin are reported to be 

 particularly active hemolytically, while ricin, abrin and robin are 

 characterized by their agglutinating properties, hemolysis being pro- 

 duced only by the use of relatively larger amounts. The serological 

 properties of ricin have been widely investigated. 



* Washed cells are devoid of free lecithin which is the necessary suhstrate for the 

 enzyme of venom to produce the hemolytic "lysocithin." 



