1903.] 



Action of the Poison of the Hydrophidce. 



489 



but without the addition of the venom, used as controls. These control 

 solutions showed no dissolution of the red corpuscles after twenty- 

 four hours. From 5 to 10 cubic centigrammes of blood were added 

 to from | to 1 c.c. of the isotonic solution of the poison, varying 

 strengths of the latter being tested in this way. Pigeon's blood is 

 specially well suited for these experiments, as the bodies of the 

 corpuscles are dissolved while the nuclei remain visible. It was found 

 that a l-in-1000 solution of Cobra venom (1 milligramme in 1 c.c.) 

 produced a very rapid solution of the red corpuscles, which had all dis- 

 appeared in seven minutes. A l-in-20,000 solution took a much longer 

 time to produce complete dissolution, namely two and a half hours. 

 In the case of human blood a 1-in-l 0,000 solution of cobra venom dis- 

 solved the whole of the red corpuscles in from fifteen to thirty 

 minutes, while one of a strength of 1 in 20,000 took about one hour 

 to do so. A l-in-100,000 solution had very much less effect, having 

 produced only a slight diminution in the number of the red corpuscles 

 within one hour's time. The white corpuscles were not dissolved by 

 the venom in the strengths used. 



Let us now compare these data with those obtained with the 

 poison of the Enhydrina, bearing in mind the much greater potency 

 of the latter as compared with Cobra venom. The poison of the 

 Enhydrina was mixed in the same way as above described with 

 the blood of pigeons and with human blood, in strengths of 1 in 1000 r 

 with the result that at the end of one or two hours there had been 

 no appreciable dissolution of the red corpuscles. On testing again 

 several hours later, slight dissolution was found to have taken 

 place, and by this time the solution also showed naked-eye evi- 

 dence of commencing haemolysis. After having been kept at room 

 temperature (from 70 3 to 80° F.) for twenty-four hours the dis- 

 solution appeared to be complete, but, on examination with the 

 microscope, a few red corpuscles were still found to be undissolved,, 

 showing that even after this lapse of time the hsemolytic change was 

 not quite complete. The poison of the Disteira cyanocincta and the 

 Hydrophis cantoris were also tested in the same way with precisely 

 similar results, namely, that a strength of 1 in 1000 had no appreciable 

 hemolytic effect at the end of one hour, but caused nearly complete 

 dissolution at the end of the course of twenty-four hours. This is 

 about the same effect as is brought about by a solution of Cobra venom 

 of a strength of 1 in 100,000, although Cobra venom has a potency o£ 

 only one-tenth that of the poison of the Enhydrina. Thus we find 

 that in proportion to its potency the poison of the Cobra has about 

 1000 times as great a hsemolytic effect on the red corpuscles of warm- 

 blooded animals as has that of the Enhydrina. We have already seen 

 that the latter poison produces no blood-stained effusion at the site of 

 the injection of a fatal dose, evidently on account of the strengths used 



