ANAPHYLAXIS. 499 
occur in certain individuals with a variety of substances which 
are quite harmless to the great majority. 
Some French scientists have sought to show that horse serum 
if injected in comparatively large doses is distinctly dangerous. 
Their theories were based upon experiments with various small 
animals. However, in the preparation of sera, including that 
used for the cure of snake venom poisoning, the horse is the 
favourite animal, consequently horse serum has been used for a 
considerable number of years by veterinary surgeons and medical ° 
men with the most satisfactory results. There is no evidence 
so far to show that anti-venene serum, if injected ‘n excess, will 
cause any serious toxic effects. I have recently been in communt- 
cation with the highest authorities on the subject, who assure me that 
there is absolutely no danger to life if large doses of it are injected. 
I have repeatedly injected animals with very large doses of 
anti-venene serum. The only toxic symptom was a more or 
less inflamed appearance about the site of the injection, or a 
sort of nettle-rash. In most instances there were no toxic effects 
after the first, or a second injection if it was made within four 
or five days of the first. If the second one was made two 
weeks or more after the first, a nettle-rash and sometimes slight 
fever appeared. It, however, passed off in two or three days. 
Occasionally in severe cases of poisoning by snake venom, 
when the patient is rather far gone before treatment is applied, 
it is necessary to inject him copiously with anti-venene serum, 
in order to save his life, and it is as well to know that the serum 
if injected in excess will not produce any serious toxic effects. 
The slight anaphylaxia produced is of no practical importance. 
Anti-venene is being used largely in India, and the French 
possessions in Northern Africa, with the most satisfactory results. 
When considered necessary, medical practitioners need not 
hesitate to inject 50 to 100 cubic centimetres (2 to 4 ounces). 
However, owing to the possible development of hypersensibility 
(anaphylaxia) to horse serum, injecting the serum direct into a 
vein in large doses should not be employed in those cases where 
horse serum has been injected more than fourteen days before, 
even if it be two years since the last injection, unless the gravity 
of the symptoms justify this risk. In severe cases of snake 
venom poisoning, in my opinion, there should be no hesitation 
in using serum freely. 
