458 
PHYSIOLOGY. 
Third .—The modification of the vegetability of the cultures 
is associated with the attenuation of their virulency. If a culture 
is exposed to the sun, and if from this, at different times between 
the first and the 30th hour, a part of it is taken, sufficient to 
fecundate another culture, and to inoculate two guinea-pigs, a 
double series of interesting experiments may be started. While 
the cultures will become less and less cloudy, and the first marks 
of vegetation will be slower to show themselves, the guinea-pigs 
will first die with anthrax in the ordinary time, then at a later 
period, and at last will resist the inoculation. In the last case, 
the survivor will have obtained a certain immunity, varying in 
strength. It is towards the 30th hour of insolation that the cul¬ 
tures have become vaccinal. 
Colored rays, which have little or no effect upon the vegeta¬ 
bility or vegetation, have not produced an attenuation of the 
virulency. Cultures which have proceeded from spores that were 
exposed to the sun for a time not long enough to stop all vegeta¬ 
bility, seem yet to possess a great virulency. 
Fourth .—It is beyond doubt that sunlight can effect the 
attenuation of the'virulency of cultures of bacillus authracis, and 
transform them into a series of vaccines, as certainly as heat will. 
What remains to learn is whether the attenuation obtained by 
the sun’s action is susceptible of preservation, nearly intact, and 
can be transmitted by generation. This will be the subject of 
further study. If the results were positive, one might judge of 
the ease and simplicity which would characterize the preparation 
of carbuncular vaccine during the summer. Whatever these may 
be, the facts at present known demonstrate that light is a biolog¬ 
ical agent of very great importance in the world of the infinitely 
minute.— Acad, des Sciences. 
Pasteur’s Inoculations. —Pasteur has now treated seven 
Americans for the purpose of preventing hydrophobia. Of these 
it is not positively known that a single one of them was bitten 
by a rabid dog, unless it is Kaufman. The daily papers of the 
present week announce that the dog which bit him bit another 
dog, which latter has had signs of hydrophobia .—Medical Record. 
