854 
remarks on micro-organisms. 
countrymen. In March, 1878, an experiment was made at 
the Brown Institution, at the suggestion of Dr. Burdon 
Sanderson, of inoculating a calf with the blood of a guinea- 
pig which had died of splenic fever, which is exceedingly 
fatal to rodentia. The result was that the calf took the 
disease, but in a mild form, and recovered from it; and a 
similar fact w r as observed in two heifers treated in the same 
way.* 
This line of inquiry has since been followed up by Dr. 
Sanderson's successor at the Brown Institution, Dr. Green¬ 
field, with the view of ascertaining whether the milder form 
of the disease in cattle, resulting from inoculation with the 
blood of rodentia affected with it, confers upon the cattle 
immunity from the complaint in its fatal form; or, to use again 
M. Pasteur's expression, whether the cattle have been vacci¬ 
nated with reference to anthrax. And I have great pleasure 
in being able to inform the Section, by Dr. Greenfield's per¬ 
mission, that the question has been answered in the affirm¬ 
ative ; and that one bovine animal, inoculated seven months 
ago with virus from a rodent, has proved itself, on repeated 
inoculations, entirely incapable of contracting splenic fever, 
remaining free from either constitutional or local manifesta¬ 
tions of it. 
And now to return to M. Toussaint, who has made obser¬ 
vations with regard to this same subject of vaccination against 
anthrax fraught with the very deepest interest. The question 
arises, with regard to effective vaccination, using the term in 
Pasteur's general sense: Is it essential that micro-organisms 
should develop in the blood of the animal in which immunity 
from further attacks of the disease is to be secured? or is it 
possible that the necessary influence upon the system may 
be exerted by merely chemical products of the growth of 
that organism in some other medium ? With the view of 
approaching the solution of this question, M. Toussaint has 
performed experiments of injecting into the blood of healthy 
sheep blood taken from an animal affected with splenic fever, 
but deprived of the Bacillus anthracis. Taking blood from a 
sheep just on the point of death, when the bacillus has pre¬ 
sumably produced all its possible effect upon the vital fluid, M. 
Toussaint proceeds to deprive it of the living bacillus in either 
of two ways—by filtration or by destroying the vitality of the 
organism. The former he effects by mixing the blood with 
three or four parts of water, and then passing it through about 
twelve layers of ordinary filter-paper. The bacillus, in con- 
* See Report, on Experiments on Anthrax by Dr. Sanderson ”( Journal of 
the Royal Agricultural Society of England , vol. xvi, s.s., part 1). 
