ANALYSIS of continental JOURNALS. 28i 
that, by the addition of water, the virulent granulations be¬ 
come separated and deposited, leaving above them a stratum 
which is inactive during the repose of the mixture; if, 
however, it is agitated, these granules are stirred up and 
communicate the virulent property to all its parts. M. 
Chauveau has also noted, with regard to this subject, a fact 
the importance of which few can overlook : he has ascertained 
that the vaccine diluted with five times its weight of water 
is as certain in its action as concentrated virus; he has even 
been successful in obtaining inoculations with vaccine matter 
mixed with a hundred and fifty times its weight of water, 
though less constantly. What is still more worthy of remark 
is that, in these cases, the vaccinal eruption comports itself 
in the same manner; the pustulation pursues an absolutely 
normal course, and presents characters identical with those 
of the pustulation produced by inoculation with pure vaccine 
matter. 
Giving a wider extension to his researches, M. Chauveau 
has applied the same method to determine the virulent prin¬ 
ciple in variolous pus and that of glanders. Without entering 
into the detail of these facts in this place, it may be sufficient 
to state that these experiments have led M. Chauveau to the 
same conclusions; in the pus of variola and glanders, as in 
the vaccinal liquid, the specific activity which constitutes its 
virulence resides exclusively in the elementary corpuscles 
suspended in these humours. Therefore studying the viru¬ 
lent corpuscles in the closest manner, he has remarked that 
they may be washed without losing their specific properties, 
and that their prolonged sojourn in water does not confer 
their virulence on that fluid. 
It is in starting from these experimental results, and 
having recourse to other observations made in cases of variola 
ovina, and the cattle plague, that M. Chauveau has proposed 
a theory of mediate contagion in these diverse infectious 
maladies. He has also broached in these experiments a 
question of the highest interest in pathology and hygiene. 
In medicine there prevails an erroneous opinion with regard 
to the innocuousness of virulent substances when introduced 
into the stomach; it being supposed that they are digested 
and become inactive when they reach the intestinal canal. 
M. Chauveau has demonstrated that it is not so, and his ex¬ 
periments in this direction have been more particularly 
carried on with tuberculous matter. He is still engaged in 
a series of experimental and comparative researches on simple 
inflammatory humours, virulent humours, and other analogous 
morbid productions. 
