PHYSIOLOGICAL ACTION OF VENOM OF BLACK SNAKE. 155 
Haemoglobin which has been dissolved out of the corpuscles 
under the influence of the venom possesses a more than ordinary 
tendency to crystallize, as is exemplified by the following experi- 
ment :—10 c.c. of defibrinated blood of a dog were poured into 
a dry test-tube containing ‘0001 gramme of venom, and placed 
in an incubator at 38°C. over-night. When examined in the 
morning the contents of the tube were solid with haemoglobin 
crystals, so that the mass could only be removed with a spoon, 
The haemoglobin in the crystals was in part converted into 
methaemoglobin. A solution of well washed crystals showed the 
absorption spectrum of methaemoglobin as well as oxyhaemoglobin, 
so that it would appear that both derivatives of haemoglobin were 
present together in the crystals. As time went on, the amount of 
oxyhaemoglobin in the crystals diminished and that of methaemo- 
globin increased. 
This conversion of oxyhaemoglobin into methaemoglobin does 
not occur under the influence of the venom itself but is due to 
organisms. It occurred in all the control tubes which were not 
sterile, but took place in these much Jater than in those that con- 
tained venom. This is probably to be explained by a much greater 
growth of the organisms in the blood which had received a small 
admixture of venom. I shall presently show that venom destroys 
' the power possessed by normal serum to inhibit the growth of 
Some micro-organisms, which would explain why they should 
grow more readily in those test tubes to which venom had been 
added. 
: The process of corpuscle destruction can be observed on a warm 
: Stage under the microscope, in the same way as with frog’s blood. 
: When mixed with salt solution containing ‘017, of venom the 
field is markedly coloured with haemoglobin after thirty minutes. 
Tn two hours the corpuscles are largely destroyed, and in ten 
hours have entirely vanished and crystals of haemoglobin 
sabe — They do not swell up, but become globular, the haemo- 
globin passes out of them and the stromata become less and less 
distinguishable until they can no longer be discerned. 
