1893. ON PASTEUR’S METHOD OF INOCULATION. 10g 
Since there is no proof that the toxic principle is retained in the 
body—indeed, it has been shown that in a diseased or vaccinated 
animal the toxic products are eliminated in the urine—immunity con- 
ferred by inoculation, if of more than momentary duration, cannot be 
due to the actual presence of the poison. 
M. Bouchard,? again, has shown that the toxic products of 
bacterial growth contain two antagonistic principles, which he has. 
termed amectasine and ectasine. Possibly these may correspond to the 
two principles of MM. Rodet and Courmont. 
According to Cohnheim, the passage of the white corpuscles of 
the blood through the vessels (diapedesis) is the dominant pheno- 
menon of inflammation; and, according to MM. Massart and 
Brodet, these white corpuscles possess a certain chemical irritability, 
which causes them, when placed in solutions containing the products. 
of bacterial growth, to pass from those parts where the solution is 
more dilute to those where it is more concentrated. These facts are 
connected in an interesting manner with inoculation. 
Local inflammation is one of its phenomena, and it may be 
supposed that the attractive action of the toxic principle of the 
vaccine has caused diapedesis of the leucocytes. 
According to M. Bouchard, however, it is only the principle he 
has named ectasine which promotes diapedesis; the other, anecta- 
sine, hinders it, and has been used by him for the prevention of 
hemorrhage. When the leucocytes, thus drawn to the seat of local 
inflammation, meet with any microbes, they envelop and digest them. 
This is the phenomenon of phagocytosis. It may be held to explain 
a temporary immunity from disease when subject to infection; for 
supposing an animal is inoculated with the toxic principle, then the 
leucocytes are drawn to the seat of inoculation by the attractive force 
of the ectasine. In their consequent state of activity, and outside 
their proper vessels, they are in a favourable state for meeting with 
and destroying, accidentally or purposely, introduced microbes. This 
would explain immunity from disease existing mmediately after inocula- 
tion, which is, perhaps, all that has really been experimentally 
proved. But it can scarcely be supposed that this abnormal activity 
of the leucocytes, and their readiness to attack the microbes, could be 
retained for any length of time. 
It may be further added that Pasteur himself has expressed his 
conviction that the vaccinal matter of rabies is really a toxic prin- 
ciple produced by the microbe, and that in the case of the spinal cord 
of the rabbit exposed to heat and dry air, the microbe is destroyed 
and not modified. 
G. W. BuLman. 
9 Comptes Rendus, vol. cxiii., p. 624. 
