SHCRETION AND COLLECTION OF VENOM IN SNAKES 149 
The quantity of venom secreted by the glands varies greatly, 
according to the length of time which has elapsed since the animal 
took its last meal, and in accordance with a number of other con- 
ditions not very easy to determine. 
The Common Viper of Europe yields scarcely 10 centigrammes 
of poison, while an adult Indian Cobra may excrete more than 1 
gramme. 
Freshly collected venom is a syrupy liquid, citron-yellow or 
shghtly opalescent white in colour. : 
When dried rapidly in vacuo or in a desiccator over calcium 
chloride, it concretes in cracked translucent lamellae like albumin 
or gum arabic, and thus assumes a crystalloid aspect. In this 
condition it may be kept indefinitely, if protected from light, air, 
and moisture. It dissolves again in water just as readily as 
albumin or dried serums. 
I regularly weighed the dry residue from eleven bites made 
on a watch-glass by two Naja haje, received at my laboratory from 
Egypt at the same time, and placed in the same case. Both snakes 
were approximately of equal length, 1,070 millimetres. Through- 
out the entire course of the experiment, which lasted one hundred 
and two days, neither of them took any food, but they drank water 
and frequently bathed. 
The results that I obtained are shown in the table on next page. 
It will be seen that in one hundred and two days, an adult Naja 
haje is capable of producing on an average 0°632 gramme of liquid 
venom, equal to a mean weight of 0‘188 gramme of dry extract ; 
and we may conclude that 1 gramme of liquid gives 0°336 gramme 
of dry venom. 
In Australia it has been found by MacGarvie Smith, of Sydney, 
that Pseudechis porphyriacus yields at each bite a quantity of 
venom varying from 0'100 gramme to 0°160 gramme (equal to 0°024 
gramme to 0‘046 gramme of dry venom), and that a Hoplocephalus 
curtus (Tiger Snake) yields 0°065 gramme to 0°150 gramme of 
