160 METHOD OF PREVENTING DEATH FROM SNAKE BITE, 



The above results are very encouraging, as the Viperine 

 poisons are much less powerful, weight for weight, than are 

 most of the Colubrines and Hydrophidse, so that the amount of 

 venom ejected by them can seldom, if ever, be more than two 

 or three times a lethal dose for man. 



In the course of the experiments it was observed that, even 

 when the incision mas made only 30 seconds after the injection 

 of the poison into the subcutaneous tissues, a distinct blood- 

 stained effusion is found, which serves as a very useful guide to 

 the location and limits of the injected poison ; after five or ten 

 minutes the effusion is more extensive, and in these cases the 

 incisions were prolonged up the limb for about 2 inches in 

 order to try and destroy as much of the venom as possible 

 The fact that as favourable results have been obtained after 

 five minutes as after half a minute, may very possibly depend 

 on the effusion noted materially checking the absorption of the 

 poisons, so that at the end of that time the rate of absorption 

 may become very much less rapid than during the first few 

 seconds after its injection. That a very rapid absorption occurs 

 during the first few seconds after the injection (probably on 

 account of the action of the poison in preventing clotting of the 

 blood locally) is certain, for it was showm by Fayrer many years 

 ago that a dog bitten in the tail by a full-sized cobra died, in 

 spite of the tail being cut off between the bitten part and the 

 body a few seconds after the bite. In such cases, however, the 

 dose received is relatively much larger than could be injected 

 by a cobra in the case of such a large animal as man, so that in 

 practice (except in the very rare cases where the poison is 

 injected directly into a vein) a fatal dose may not enter the 

 system for some considerable time after the bite. This 

 probability is supported by the fact that, in the case of 

 Colubrine poisons at any rate, the minimal lethal dose is the 

 same whether the venom is given subcutaneously or intra- 

 venously, yet it takes one or two days to produce death when 

 injected under the skin, but only 5 — 20 minutes when inserted 

 into a vein, so that under the former conditions the whole of the 

 poison does not enter the circulation for a long period. These 

 facts suggest the hope that the method of treatment here 



