PROPHYLAXY OF INFECTIOUS DISEASES. 
733 
that disease there is but little chance of its recovery. The 
tetanic toxine produced on the surface of an infected wound is 
absorbed at once and so acts upon the nervous cells that it alters 
them in an irremediable way ; and when the first symptoms ap¬ 
pear it is not the beginning of the disease, but of the end. It 
is too late to cure, and if the dose of absorbed toxine is sufficient 
to kill, you may use all the serum you wish, it will not act. 
On the contrary, if you use it as a preventive in almost insigni¬ 
ficant doses, io cc. for a iooo-pound horse, the horse will be 
protected. But tetanus, as you know, like anthrax and rouget, 
is a disease of the soil; it is the sad privilege of some regions ; 
there are countries which have tetanus as well as those which 
have anthrax. In these, cases of tetanus are so frequent after 
surgical operations that veterinarians do not dare to perform 
them. The use of serum has removed all danger. Veterina¬ 
rians and owners of animals have a security which was wanting 
for a long time. I have published the result of several thou¬ 
sand observations all gathered from severely infected districts ; 
not one of the 4000 animals treated by this method has taken 
lockjaw. 
There is no discovery which has been accepted and has 
spread so rapidly as this, and there has been no trouble, as every 
one knew of the dangers of the disease. The injection protects 
from a great risk, the expense is trifling and severe losses are 
spared. 
Tetanic serotherapy is also the best mode of treatment for 
lockjaw; if the serum does not always succeed in curing, there 
is no doubt that if recovery takes place, it is quicker and the 
convalescence is shorter. There is every advantage then in 
using the serum, providing the owner is not told of a sure recov¬ 
ery, but the only chance of cure is by resorting to this mode of 
treatment. 
In animals powerfully immunized against pleuro-pneumo- 
nia serum has also preventive and curative properties ; but the 
short duration of the immunity that it gives does not allow us to 
substitute it for inoculation. It would be better to begin first 
