EXPERIMENTAL VENOM POISONING IN ANIMALS 117 



Lamb demonstrated that the venom of Daboia russellii, when injected 

 subcutaneously into pigeon, kills the bird in a very short time, from 75 seconds 

 to 10 minutes. In these cases the post-mortem examination revealed the 

 constant presence of extensive and solid intravascular clotting in the auricles, 

 and sometimes in the right ventricle of the heart, and in the pulmonary vein 

 and portal system of veins. If the dose exceeded many times a minimal 

 lethal dose it did not change the result much, except that the larger the amount 

 of venom injected the more rapidly the symptoms appeared, and the sooner 

 death took place. The thrombosis was more extensive and more solid than 

 in those cases in which only one minimal lethal dose was given. 



The results obtained by intravascular injection of this venom into monkeys 

 do not essentially differ from those obtained in the foregoing cases. Death 

 often took place in a minute after the injection; in such instances there is 

 much gasping, convulsions are constant, and the pupils are dilated. Solid 

 clots are usually seen in the pulmonary vessels, portal veins, superior and 

 inferior venae cavae, aorta, and sometimes the right cardiac ventricle. If fluid 

 blood is present it usually remains uncoagulated. The amount of venom 

 given in this series was from o.ooi gm. to 0.0025 gm. and the time of death 

 varied from i to 5 minutes. 



In rabbits exactly similar symptoms and final results have been obtained 

 by Lamb, but he observed more pronounced convulsions and gasping. The 

 amount of the venom sufficient to produce fatal intravascular clotting is as 

 small as 0.000075 g"^- to o.oooi gm. given intravenously. Death results 

 within 7 to 8 minutes. 



Lamb described the chronic form of daboia toxication. In monkeys there 

 are symptoms local and general. Severe haemorrhages occur around the 

 point of injection, and considerable oedema at the dependent part sets in 

 within a few hours. In some cases the local conditions undergo resolution, 

 but in other cases the parts slough, leaving an irregularly shaped ulcer. In 

 some other cases, rapid gangrenous conditions follow the haemorrhage and 

 the animal dies of secondary bacterial infection. The general symptoms 

 are a state of depression and lethargy, loss of appetite, clammy skin, consider- 

 able cardiac depression, anaemia and in a few severe cases haematuria, and 

 bloody discharge from the rectum. (Edema may sometimes be observed in 

 penis or scrotum. 



Neither convulsion nor paralysis has been observed in these prolonged 

 poisoning cases. When death occurred in 24 to 48 hours after the injection 

 of venom, it was noted that rigor mortis was completely absent. A marked 

 diminution of coagulability is constantly noticed. 



All these symptoms are sought by Lamb in the deficiency of coagulability 

 of blood on the toxicated animals. In order to estabhsh the relation between 

 the diminution of coagulabihty of blood and the degree of illness he examined 

 the coagulabihty of the blood of a poisoned monkey and found that when the 

 blood recovers its coagulability the symptoms disappear. 



