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 
0.1 c.c., while in the second o.7 c.c. neutralized 18,620 units, making 266 per 
o.1 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 
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1100 
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700 
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500 
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100 

0 5 10 20 30 40 sO 60 70 0 0.05 0.1 0.2 0.3 0.4 0.5 0.6 0.7 
Fic. 3. Fic. 4. 
If we exclude toxoids from the reaction between venom and antivenin, we 
can make a direct comparison of the neutralized hemolyzing units per 0.1 C.c. 
of antitoxin in both series. In the first series 0.1 c.c. neutralized 2,000 + 13 = 
153 minimal hemolyzing doses, and in the second 1,428 + 7 = 204 minimal 
hzmolyzing 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 hemolytic 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 r2 hours from 2,000 to 250 minimal 
hemolyzing 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. 
