6o New Researches on Canine Madness . [February 
death as in ordinary cases. The question may here be raised 
whether rabies is always fatal in wild animals, or whether, 
as certain fadts suggest, recovery is not uncommon ? M. 
Pasteur’s experiments have not, of course, shown whether 
idiopathic rabies differs at all in its character from the 
disease as communicated by inoculation. In one experi- 
ment, made in 1881, three dogs were inoculated. Two of 
these quickly became rabid, and perished, whilst the third, 
after having manifested the first symptoms, recovered. This 
last dog was twice re-inoculated in 1882, the poison being 
brought in contact with the brain, but did not become rabid. 
Here, therefore, we have a case of the disease in a mild form 
proving a prevention against future infection. This result 
M. Pasteur considers the first step towards discovering a 
means of preservation from rabies. He possesses at present 
four dogs which are proof against the infection, whatever 
may be the method of inoculation used and the virulence of 
the matter; whilst other dogs, inoculated with the same 
virus, invariably perish. M. Pasteur raises the question 
whether these four animals owe their impunity to sponta- 
neous recovery from a mild attack which may have escaped 
observation, or whether they are naturally and exceptionally 
refradfory to the infection ? This question he is now endea- 
vouring to decide. 
M. Paul Bert has also called attention to some experi- 
ments on the same subject which he made in the years 1878 
and 1879, and which have been to a great extent overlooked. 
He effected, on one occasion, the total reciprocal transfusion 
of the blood between a healthy dog and one in the height of 
rabies. The former, though kept afterwards under observa- 
tion for a year, showed no signs of madness, whilst the 
general condition of the mad dog was somewhat improved, 
and it survived, apparently, forty-eight hours longer than it 
would otherwise have done. 
M. Bert has also examined in which of the constituents 
of the slaver of a rabid dog the virus is contained. This 
slaver is a very complex mixture, containing — in addition to 
the saliva of the parotid, the maxillary, and sublingual 
glands — the mucus of the mouth and of the respiratory 
passages. To decide this question he has inoculated series 
of dogs with the mucus and with the liquid expressed from 
the different salivary glands of dogs killed in the height of 
rabies. The salivas — in the stridt sense of the term — have 
never communicated rabies, whilst the mucus from the 
respiratory organs has done so, and must be considered as 
the deadly portion of the slaver. This explains the great 
