108 
Pasteur and his Work, 
manner as the anthrax rods or spores. The discovery of the 
microbe was made by Detmers in America (1882), and about 
the same time by Pasteur and Thuillier in France. Klein had 
previously found a bacillus, but this is not now acknowledged as 
the active agent. The germ exists throughout the body of the 
diseased pig, and especially in its excreta, which are very viru- 
lent. Infection is easy by the digestive organs ; and, besides 
other modes of contamination, the food may receive the microbes 
by diseased mice, or through the medium of rats, flies, birds, <Scc. 
In 1883, Pasteur made known a method of attenuating the 
virus, which, simple and effective, offers as certain protection 
against swine-plague, when inoculation is properly performed, 
as anthrax inoculation does against that malady. He found 
that when a pigeon was inoculated in the chest with the 
microbes of the disease, it died in six or eight days. When a 
second pigeon was inoculated from this, a third from it, and so 
on in succession, the microbe acclimatised itself in pigeons ; so 
that death ensued more rapidly, and the blood of the last pigeon 
assumed much more virulence when introduced into pigs, than 
the most infectious products of a pig that had died of the natural 
disease. But the passage of the microbe through rabbits had 
quite a different result. When inoculated from a diseased pig, 
these creatures all speedily perished, but cultures of their blood 
in sterilised media became progressively easy and more abundant, 
the microbe somewhat changing in appearance. When pigs 
were inoculated with the blood of the last rabbits, and the 
results were compared with those obtained from the first, it was 
discovered that the virus had gradually lost its power ; and though 
the blood of these rabbits made pigs very ill, it ceased to kill 
them. On recovery, they were proof against the fatal disease. 
In various parts of France, this swine vaccination has been 
carried out ; but perhaps the most carefully conducted and ex- 
tensive experiments were carried out in the Grand Duchy of 
Baden, in 1884, to test the value of the measure. In that 
country swine-plague had caused heavy losses for many years, 
and in 18G5 and 1871 commissions were appointed to report 
upon it. In 1884 it was arranged that a trial of vaccination 
should be made, under Pasteur's direction, the experiments to 
be carried out by one of his assistants, and the inoculating 
material and instruments to be supplied from his laboratory. 
The experiments were carried out at fifteen places on 237 pigs 
of different breeds and ages, and were under the observation of 
selected veterinary surgeons from Berlin, Munich, Stuttgart, 
Hesse, Alsace-Lorraine, Luxemburg, and Berne, as well as 
others. All the pigs were in perfect health, and the inocula- 
tions were performed in a similar manner to those on the sheep 
