INTERACTIONS BETWEEN VENOM AND ANTIVENIN 



253 



Again, a remark may be made here as to the anti-haptin units contained in 

 the antivenin employed in the above two experiments. In the first experi- 

 ment 1.3 c.c. of antivenin neutralized about 20,800 units, making 160 per 

 o.i c.c., while in the second 0.7 c.c. neutralized 18,620 units, making 266 per 

 o.i c.c. of the serum. As these estimates are made with invisible factors 

 (toxoids) we are at a loss how to fix the cause of this difference. If we assume 

 that in the first venom there was also toxoid, although not shown in the 

 spectrum, of an affinity equal to the toxin it would be easy to account for this 

 difference. In this case we must assume that the amount of uncalculated 

 toxoids was the difference. 



400 

 300 

 200 



iioo 



1000 

 900 

 800 

 700 

 600 

 500 

 400 

 300 

 200 

 100 



ao 30 40 

 FIG. 3. 



If we exclude toxoids from the reaction between venom and antivenin, we 

 can make a direct comparison of the neutralized haemolyzing units per o.i c.c. 

 of antitoxin in both series. In the first series o.i c.c. neutralized 2,000 -f- 13 

 153 minimal haemolyzing doses, and in the second 1,428 -r- 7 = 204 minimal 

 haemolyzing doses. This shows that the antitoxin used in the second series 

 had about 1.5 times more strength than that in the first. The comparison 

 made in the other way, namely, including toxoids, shows also about the same 

 ratio, as in the second series the serum was 1.4 times stronger. It is not 

 improbable that the antivenins employed in these two series were not of the 

 same strength. 



Myers then proceeded to examine whether or not the deteriorated solutions 

 of cobra venom have lost their haemolytic as well as their combining powers. 

 The venom solutions were of 0.2 per cent and were made in an 0.8 per cent 

 salt solution. One of the most striking facts brought out by him is that 

 when the venom solution of the said strength was kept at 35 C. for 6 hours 

 its strength dropped from 2,000 to 333, in 12 hours from 2,000 to 250 minimal 

 haemolyzing doses per milligram. On the other hand, their combining prop- 

 erty for antivenin remained practically unaltered. If there was any diminu- 

 tion in this power it was only trifling. 



