700 
W. S1LBEKSCIIMIDT. 
rabbits. To protect animals to the last, there would have been 
required a more active serum. Nevertheless, it is permitted 
to affirm, from the facts mentioned and numerous analogous 
results, that the serum of vaccinated animals, injected in new 
rabbits, has a preventive, vaccinating and therapeutic action. 
This action is much more manifest after the intravenous in¬ 
jection than after the subcutaneous inoculation. A fact to 
notice, the dog which had resisted several times to inocula¬ 
tions of 2.5 cc. of virulent blood and which consequently was 
much more vaccinated than the rabbits, has furnished a very 
little active serum ; which is due probably because he had re¬ 
ceived a quantity of toxine relatively much less to its weight. 
I believe I can endorse the opinion expressed first by Mr. 
Metchnikoff, that the preventive power of the serum of vac¬ 
cinated animals does not depend on the state of immunization 
of the animal, but is in direct proportion to the quantity of 
toxine injected. 
The therapeutic action of the serum is about as great as its 
preventive, the last two mentioned experiments prove it; the 
rabbits treated several hours after the inoculation of the virus, 
at a moment where they already exhibited a noticeable eleva¬ 
tion of temperature, have resisted as long as those which have 
received the preventive serum before the injection of the 
virus. It can be hoped that by increasing the dose of the 
toxine to inject, one will succeed, by the injection of the 
serum, not only to protect, but also to cure animals already 
diseased. 
\ 
On different occasions I have received small doses of cul- 
ture with the serum of vaccinated animals ; this mixture culti¬ 
vated, has, after a few minutes, a few hours or a few days, 
regularly given a culture, and its inoculation to various ani¬ 
mals has brought on death as rapidly as the injection of cul¬ 
ture without serum. 
Conclusions .—1st. The serum of animals vaccinated against 
swine plague has [no bactericide action in vitro , and injected 
with virus does not postpone the death of the rabbit. 
2d. Two rabbits have resisted an injection of virulent cul¬ 
ture of swine plague which has killed the witnesses, after the 
* m 
! 
