64 CANINE DISTEMPER 
little to my astonishment, I learnt that he had feared 
after all to use the vaccine, lest it should actually cause 
an outbreak of distemper among his dogs, notwithstand- 
ing the fact that in my communication to the- Royal 
Society I was careful to describe the exact method by 
which my prophylactic is produced, showing that 
sterilisation of the fluid and the consequent killing of 
all living micro-organisms is an essential factor of the 
process. It is doubtless true that any protective influ- 
ence against distemper which the vaccine is capable of 
affording is due to the fact that its inoculation gives rise 
to what is practically a mild attack of the disorder, but 
with this most important difference from the natural 
disease—that owing to the method of the preparation of 
the vaccine it is absolutely impossible for an inoculated 
dog to infect with distemper other dogs with which it 
may come into contact. I provided Mr. Sewell with 
material for testing purposes, but he did not succeed in 
producing in puppies by its use any marked immunity. 
“On looking over the temperature charts of the animals 
inoculated by him, it is apparent that in no instance did 
any reaction follow, marked as it would have been by 
some rise of temperature, and that therefore little or no 
immunity could be expected to ensue. 
“Tn carrying out inoculations, it is obviously essential 
that a sufficient dose should be employed if any measure 
of success is to be obtained. Herr Carl Hopf, in a letter 
to me, rightly lays stress upon this point, stating that 
whereas all the vaccinations performed by himself had 
proved successful, notwithstanding prolonged exposure 
of the inoculated animals to the infection of distemper, 
on making inquiry as to certain alleged failures reported 
to him he found that only about 1 c.c. of the vaccine had 
been injected in each instance. In conclusion, I would 
suggest that where the first injection is followed by no 
