PROTECTIVE INOCULATIONS. 829 
animal, when inoculated into the dog, no longer produces fatal rabies; 
and that dogs so treated are subsequently immune. 
In his address before the International Medical Congress at Copen- 
hagen (August 11th, 1884), after a review of the facts developed during 
his experimental researches made during the preceding four years, 
Pasteur gives an account of the test made by a commission, appointed 
by the Minister of Public Instruction, to determine the efficacy of his 
method as applied to the protection of dogs. Hesays that he gave to 
the commission nineteen dogs which had been rendered refractory 
against rabies by preventive inoculations. These nineteen dogs and 
nineteen control animals, obtained from the pound without any selec- 
tion, were tested at the same time. The test was made upon some of 
the animals of both series by inoculation with virulent material upon 
the surface of the brain, and upon others by allowing them to be bit- 
ten by rabid dogs, and upon still others by intravenous inoculations. 
Not one of the protected animals developed rabies; on the other 
hand, three of the control dogs out of six bitten by a mad dog devel- 
oped the disease, five out of seven which received intravenous inocu- 
lations died of rabies, and five which were trephined and inoculated 
onthe surface of the brain died of the same disease. In a subsequent 
report the commission, of which M. Boulley was president, stated that 
twenty-three protected dogs which were bitten by ordinary mad dogs 
all remained in perfect health, while sixty-six per cent of the control 
animals, bitten in the same way, developed rabies within two months. 
In his communication of October 26th, 1885, Pasteur reports his 
discovery of the fact that the virulence of the spinal cord of a rabbit 
is gradually attenuated by hanging it in a dry atmosphere, and is 
finally entirely lost; also that he had been able to make a practical 
application of this discovery in the protection of dogs by means of 
successive inoculations beneath the skin of an emulsion of spinal mar- 
row attenuated in this way. The first inoculation was to be made 
with a portion of spinal cord which had been kept long enough to de- 
prive it of all virulence, and this was followed by daily inoculations 
with more virulent material, until finally material was used from a 
cord only a day or two old. 
With reference to his first inoculations in man, Pasteur says: 
‘Making use of this method, I have already made fifty dogs of various 
races and ages immune to rabies, and had not met with a single failure, 
when, on the 6th of July, quite unexpectedly, three persons, residents of 
- Alsace, presented themselves at my laboratory.” 
These persons were Theodore Vone, who had been bitten on the 
arm on July 4th; Joseph Meister, aged nine, bitten on the same day 
