138 VENOMOUS SNAKES AND THE PHENOMENA OF THEIR VENOMS 



Notechis was the strongest, Daboia the weakest, and the other two occupied 

 intermediary positions. Very remarkable is the strength possessed by the 

 notechis venom. Oxalate plasma of dog was mixed with varying quantities 

 of the solution of venom, and the time required for coagulation was noted. 

 The result may briefly be quoted here, as it furnishes us with a more accurate 

 conception of its coagulating potency. 



2 c.c. of the plasma were mixed with one drop = 0.017 c.c. of venom 

 solution of the following strengths, and the mixture placed in a bath at 40° C. 



0.1 per cent = 0.000 1 7 gm. Coagulated in less than i minute. 



0.0 1 per cent = 0.00001 7 gm. Coagulated in less than 1.5 minutes. 



0.00 1 per cent = 0.00000 1 7 gm. Coagulated in less than 15 minutes, 



o.oooi per cent = 0.000000 1 7 gm. Coagulated in less than 10 hours, 



o.ooooi per cent = 0.00000001 7 gm. Permanently fluid. 



Control Permanently fluid. 



The strength of the venoms of Pseudechis and Echis carinata proved to be 

 one-half to two-thirds of that of notechis venom, 



Martin states here that the mechanism of coagulation of oxalate or citrate 

 plasmas is independent of the presence of calcium ions, as these venoms clot 

 10 per cent oxalate plasma as rapidly as 0.2 per cent, and the action is the 

 same upon oxalate, citrate, fluoride, and magnesium sulphate plasma, and 

 also upon hydrocele fluid ^ and solutions of fibrinogen prepared from the 

 horse by the Hammerstein process. 



According to Martin, the ferment contained in the venoms does not appear 

 to be used up in the process. After a portion (5 c.c.) of plasma is clotted by 

 one drop of o.i per cent solution of the venom, it can be removed and then 

 another portion be added. This will clot. This process can be repeated 

 four or five times, coagulation occurring more and more slowly with each 

 successive addition. The experiment can not be repeated as many times as 

 would be expected from the calculated minimal clotting dose, as presumably 

 each successive crop of fibrin carries away absorbed ferment. 



A slow deterioration of clotting power takes place when aqueous solution 

 of the venom is kept at ordinary temperature, and more rapidly if the dilution 

 be greater. The coagulating ferment of the venom dialyzes slightly, and when 

 a o.oi per cent solution is filtered through 8 per cent gelatin,^ the filtrate 

 possesses about 2^0 of the ferment power of the original solution. 



In a later section I will refer further to the specificity of fibrin ferments 

 contained in the venoms of different species of snakes. 



' Certain discrepancies exist between Martin's observations and those of Lamb in regard to the effect 

 of venom upon hydrocele fluid and also upon the concentrations of oxalate in the plasma. Lamb 

 found no action upon the hydrocele fluid, and much influence was noticed to be exerted by 

 higher concentrations of the oxalate upon the coagulating power of daboia venom. 



2 C. J. Martin, Jour, of Physiol., 1896, XX, 364. 



