1896.] on Immunisation against Serpents' Venom. 119 



•0008 c.c, -0005 c.c, and -0004 c.c. (1/1000, 1/1500, 1/2000, and 

 1/2500 of a c.c, for each kilogramme of the weight of animal ; with 

 •0003 c.c. (1/333) per kilogramme, however, the animal died. The 

 antivenene was therefore found to be so powerful as an antidote, 

 in the conditions of these experiments, that even the 1/2500 part of a 

 cubic centimetre, equivalent to about the one-hundred-and-fiftieth part 

 of a minim, acted as an efficient antidote, while even with the one-two- 

 thousandth part of a cubic centimetre not only was death prevented, 

 but there was almost no symptom of poisoning produced. In the 

 experiments of this series with one-and-a-half the minimum-lethal 

 dose, recovery occurred when the doses of antivenene were '32 c.c, 

 •3 c.c, '28 c.c, '25 cc, and •24 cc. per kilogramme; but '23 c.c. 

 and • 2 c.c. failed to prevent death. In the experiments with twice 

 the minimum-lethal dose, recovery occurred when the doses of anti- 

 venene were •Sec, •4cc., and ^35 cc. ; but •S cc and '2 cc. failed 

 to prevent death. In the experiments with thrice the minimum-lethal 

 dose, a dose capable of producing death in less than two hours, re- 

 covery occurred when the doses of antivenene were • 7 cc. and • 65 cc. ; 

 but death occurred with • 6 cc, • 55 c.c, and 5 cc. With four times 

 the minimum-lethal dose, recovery occurred with 1 • 5 c.c, 1 • 3 cc, 

 and 1 • 2 cc, and death with 1 cc. With five times the minimum- 

 lethal dose, recovery occurred with 2 * 5 cc, 2 • 2 c.c, 2 cc, 1 • 8 cc, 

 and 1 • 5 cc ; but death with 1 * 3 cc. With eight times the minimum- 

 lethal dose, recovery occurred with 2 • 6 cc. and 2 • 5 cc. ; but death 

 with 2*4 cc, 2 '3 cc, and 2 cc. And even the enormous dose often 

 times the minimum-lethal failed to produce death, or any important 

 symptoms, when it had previously been mixed with 8*5 cc. and 

 3 • 4 cc. of antivenene for each kilogramme of animal ; and it only 

 succeeded in producing death, although not until the lapse of several 

 hours, when the doses of antivenene were 3 • 3 cc, 3 • 2 c.c, • 3 c.c, 

 and 2 • 5 cc. per kilogramme. 



These results show a remarkable, an almost directly proportional 

 accordance in the increment required in the dose of antivenene for 

 each increment in the dose of venom. In the diagram, the compara- 

 tively straight direction of oblique line separating the fatal from the 

 non-fatal experiments is noteworthy, considering that the conditions 

 of the exjDcriments, in regard both to the animals and the substances 

 used, could never be absolutely the same. Indeed, from twice the 

 minimum-lethal dose of venom upwards, the addition of little more 

 than • 3 cc. per kilogramme represents the addition in the quantity of 

 antivenene required for each addition of a minimum-lethal dose of 

 venom. Apparently the antivenene is able in this proportion to 

 prevent death from almost any lethal dose of venom, however large 

 it may be (Fig. 2, overleaf). 



These results are in marked contrast with those that occur when 

 an antidote acts because of its i)hysiological properties, and they 

 alone suggest that the antidotism is rather the effect of a chemical 

 than of a physiological reaction. The indications obtained with 



