762 
ANALYSIS OF CONTINENTAL JOURNALS. 
with them alone, and comparatively with the other elements 
of the anthracoid blood. But the difficulties attending, the 
attempt to isolate them are enormous, perhaps insurmount¬ 
able when tried directly. Davaine thought he had overcome 
the obstacles when he used the placenta of a pregnant animal 
to effect the isolation; his experiment is well-known and 
often cited. A female guinea-pig in a pregnant condition 
was inoculated with anthrax matter. After the death of the 
animal its blood was full of bacteria and capable of producing 
the disease by inoculation, but that of the foetuses possessed 
neither of these features. There is no need to estimate the 
value this experiment may possess from this fact; it is c 
subject we shall have to discuss when speaking of the here¬ 
dity of virulent maladies; so we shall only examine the 
interpretation that has been put upon the results by the 
experiment. 
It is said, since of the two bloods inoculated with, that which 
contained the bacteria is alone inoculable; therefore it is that 
the bacteria are the agents that give the blood its anthracoid 
quality; the placenta, in arresting the maternal proto¬ 
organisms, hinders the foetus from contracting the malady— 
two affirmations which have not the sanction of a direct 
demonstration, as is easily shown. 
In order that the results of the experiment in question 
might indicate that the bacteria are the infecting agents in 
anthrax, it would be necessary to prove that the maternal and 
foetal blood only differed in the presence or absence of these 
particles. But this has not been done; and the fact still remains 
to be demonstrated, just as if the blood had been obtained 
from two quite independent animals, one diseased the other 
health) 7 ; one infected with the bacteria, the other exempt 
from these parasites. In this respect the experiment alluded 
to has added nothing to our knowledge of the actual elements 
of anthrax blood. 
Is it more exact to admit that if the blood of the foetus had 
not become anthracoid in this experiment, it was because the 
passage of the bacteria from the mother to its young was 
prevented by the placenta? But it is not only the bacteria 
of the maternal blood which cannot pass through the walls of 
placental vessels ; the other tangible elements, such as the 
red and white globules, globulines, &c., are no less incap¬ 
able of passing that barrier; the placenta offers the same 
impediment to them all, and there is nothing to authorise the 
opinion that one more than another is the contagiferous agent, 
and that its non-introduction into the blood of the foetus pre¬ 
vents that fluid from becoming anthracoid. The experiment. 
