364 
M. COLIN. 
animal, botli at the eighth day, have shown no virulent property' 
Outside the opening, on a radius of one, two and three centi¬ 
metres, the serous liquids, the blood of the tumor obtained by 
small scarifications equally possessed virulent properties during 
several days, and, remarkable fact, the virulency extends around 
the opening as it diminishes in its interior, either by diffusion of 
the virulent elements, or by their progressive neutralization in the 
plastic or purulent products as in the parts of tissue that gangrene 
invades. The virulency which has spread from the centre to the 
circumference of the tumor dies out in the same order; it may 
disappear completely in the centre, when at the periphery it 
retains all its activity. 
However, at a given time all the liquids of the tumor or of 
the carbunculous pustule are not equally virulent. Two amongst 
them, the serosity of the phlvctenoe and the pus from the cavity 
of the opening or of the viritiated cellular tissue, are seldom such 
and never strongly so. The cloudy serosity, somewhat loaded 
with leucocytes, ordinarily is ; very clear pus is only in half of the 
cases; but thick pus, that which loosens the eschar or carries off 
gangrenous parts, has already lost this property. 
Beyond a certain period, whether there is or not suppuration, 
whether the opening of the pustule is closed or enlarged by the 
work of gangrene, or of ulceration, whether there remains or not 
marks of irritation, all virulency disappears and the inoculation 
of the serosity, of the blood, of the solid particles sloughed off 
from the pustule, all remain entirely sterile. 
There are. then, in the carbunculous tumor or in the pustule 
which gets well of itself, as in that which kills, virulent elements, 
associated in variable proportion to the serosity, to the blood, to 
the lymph, to the tissues, even to the pus in way of formation 5 
but these elements are there only temporarily, they change places 
before disappearing, rarify in certain parts, condense together in 
others, whither they are to die in situ or spread in the whole of 
the organism. 
These peculiarities which I observe upon animals, especially 
upon the deg, explain very well the opposite results given by in 
oculation of the products of the malignant pustule of man. The 
facts mentioned by Mr. Raimbert, prove indeed that the insertion 
