216 THE VENOM OF HELODERMA. 



control, 3 lived longer than the controls, and 17 survived the injection. Sev- 

 eral of the mice which survived the injection were quite markedly affected by 

 the venom, showing weakness, as well as the typical changes in the eyes 

 described in one of the preceding papers. These results suggest that alkaliz- 

 ation of the venom solution interferes to some extent with the adsorption of 

 the venom by charcoal. In experiments in which the charcoal residue of the 

 alkaline suspensions was injected into mice, three survived the injection, 

 whereas eight died a considerable time after the injection. Besides interfer- 

 ing with the adsorption of venom by charcoal, the addition of an alkali to the 

 venom solution seems, therefore, to prevent the charcoal from firmly binding 

 the adsorbed venom. Identical results were obtained with various venom 

 solutions. 



The addition of 2 c.c. of either dog or rabbit serum to 7 c.c. of venom 

 solution interfered much more seriously with the adsorption of venom by the 

 charcoal. All the animals injected with the supernatant fluid from the serum- 

 charcoal-venom mixture died, 6 as soon as their controls and 12 after longer 

 periods. Of the animals injected with the residue, 6 died and 4 survived. 

 The toxic effect of the solid residue shows that although the addition of dog 

 or rabbit serum to venom solution seems to prevent almost entirely the ad- 

 sorption of venom by charcoal, still a small quantity must have been adsorbed 

 and bound rather loosely by the charcoal. 



Finally we tested the adsorption of venom by a mixture of equal parts of 

 charcoal and lecithin (Kahlbaum). In this experiment a suspension of leci- 

 thin was obtained by rubbing and finely distributing 0.07 gram of lecithin in 

 7 c.c. of the venom solution. To this emulsion a quantity of charcoal equal 

 to one-fourteenth of the bulk of the solution was added. Of the mice injected 

 with the supernatant fluid five survived, and only one, which had been in- 

 jected with 13^ lethal doses of the venom, died. Of the three mice injected 

 with the residue of the charcoal-lecithin mixture, only one died. This mix- 

 ture of charcoal and lecithin acts, therefore, in approximately the same man- 

 ner as the charcoal unaccompanied by the lecithin ; the largest part of the 

 venom is adsorbed and is held by the charcoal-lecithin mixture and in such a 

 manner that it can not be absorbed by the injected animal. It is furthermore 

 very probable that the charcoal rather than the lecithin held most of the 

 venom ; it was later found that the lecithin did not bind the venom as tightly 

 as the charcoal. 



ADSORPTION OF VENOM BY KAOLIN. 



To the solution of dried venom a quantity of kaolin equal to one-four- 

 teenth of the volume of the solution was added and the mixture kept in the 

 shaking apparatus for 2 hours 30 minutes. Of 18 mice injected with this 

 supernatant fluid 6 survived, 10 lived longer than their controls, and 2 died as 

 soon as the controls. Of these last 2 mice 1 had received a quantity of fluid 

 corresponding to 13J, the other to 6f lethal doses. These experiments indi- 

 cate that kaolin does not adsorb as much venom as charcoal, but it may, how- 

 ever, adsorb from 70 to 80 per cent of the venom. 



