CONTAGIOUS DISEASES-NEW DISCOVERIES. 
405 
for the second. To prevent its development a special vaccine 
has to be employed. Here are samples. As you observe, there 
are, again, two kinds or degrees of vaccine substance, one much 
reduced in strength, the other less so. How are they prepared ? 
By exposing the virus, taken from curbuncular tumor, at various 
temperatures. One has been exposed at 100° heat, the other at 
85°. The first gives and the second strengthens immunity in 
sheep and cattle. Both of them must be introduced at an in. 
terval of from five to eight days. 
To operate, a hypodermic syringe of the capacity of five cubic 
centimeters (a little more than one fluid drachm) is necessary, 
having a divided rod, in order to make the piston of the syringe 
to contain a given number of doses. 
The contents of one of the papers of prepared vaccine, that 
which has been exposed to a temperature of 100°, is placed in a 
mortar which must have been carefully cleaned by being passed 
through boiling water. Upon this powder two or three drops of 
water are poured and it is triturated, water being added to it un¬ 
til about ten cubic centimetres (or two a half fluid drachms) is 
used, that quantity being sufficient to dissolve the vaccine. The 
operator has then a brownish liquid, which is then run through a 
linen sifter to remove any soft particles that may have escaped 
trituration. The sieve must first have been moistened, so that 
the amount of liquid solution of vaccine after filtration is about 
ten cubic centimetres, or a sufficient quantity to fill up the 
syringe twice. 
The operation is simple. It having been demonstrated by 
experience that the tail is the best spot to vaccinate, it is done as 
follows: The hairs of the lower end of the organ being cut 
short, upon a given surface, and this being carefully washed off, 
a little cavity is made with a small trocar under the skin in such 
a way that when the tail hangs down the cavity is turned down¬ 
wards. The syringe is then introduced into the opening made 
by the trocar and the necessary quantity of liquid, from ten to 
fifteen drops, according to the age of the patient, is slowly and 
carefully introduced. A slight pressure upon the opening will 
afterwards prevent the exit of any portion of the injected fluid. 
