336 PROFESSOR JOSEPH LISTER, 
I will now return to the Bacillus anthracis, with regard 
to which I shall have again to refer to the labours of M. 
Toussaint. First, however, I must allude to the work of 
some of my own countrymen. In March, 1878, an experi- 
ment 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 was 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 a 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 
vaccinated with reference to anthrax. And I have great 
pleasure in being able to inform the Section, by Dr. Green- 
field’s permission, that the question has been answered in 
the affirmative; and that one bovine animal, inoculated 
seven months ago with virus from a rodent, has proved 
itself, on repeated inoculations, entirely incapable of con- 
tracting splenic fever, remaining free from either constitu- 
tional or local manifestations 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 dis- 
ease is to be secured? Or is it possible that the necessary 
influence upon the system may be exerted by merely chemi- 
cal 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 experiment 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 presumably produced 
all its possible effect upon the vital fluid, M. Toussaint pro- 
ceeds to deprive it of the living bacillus in either of two 
1 See “ Report on Experiments on Anthrax,” by Dr. Sanderson (‘ Journal 
of the Royal Agricultural Society of England,’ vol. xvi, s.s., part i). 
