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488 REPORT OF THE COMMISSIONER OF _AGRICULTURE, % 
the temperature had fallen below 30° F., decomposition was far ad- 
vanced. It may be that the live animals crowded upon the deadand 
thus kept the body warm. Yet this supposition is not capable of 
accounting for the rapid changes. The hemorrhagic lesions may | 
have enabled various bacteria to become distributed throughout the 
body. The heat disengaged by them during multiplication, aided by : 
the warmth of the litter, may have been sufficient to keep up the — 
process of decomposition, This post-mortem growth may also ac-_ 
count for the large number of hog cholera bacteria found in many —_ 
spleens, although the temperature of the air was, asarule, farbelow 
the point where multiplication may take place. ee 
Buzzards may carry the disease from one place toanother. When. 
the dead animals were at all exposed to view they were immediately 
attacked. Whether hog cholera bacteria are entirely destroyed in the 
digestive tract of these birds can not be said, but there is nothing in 
the range of our knowledge of bacteria which will exclude the proba- 
bility that the bacteria are not all destroyed during the digestive act, 
and that they may be scattered about by these birds. Such cbserva- 
tions should strongly urge all persons who have charge of dead ani- 
mals to bury or burn them immediately, or to have them destroyed 
in some other effectual manner. 
SOME EXPERIMENTS ON THE LENGTH OF TIME DURING WHICH HOG 
CHOLERA VIRUS REMAINS ALIVE IN THE SOIL. 
. The virus of hog cholera is quite tenacious of life, in spite of the 
fact that no spores are formed. In the report for 1886 it was shown 
that hog cholera bacteria remained alive in ordinary sterilized drink- 
ing water for about four months. They resisted drying under cer- 
tain conditions for nearly two months. During the past yearsome , 
preliminary experiments were made concerning the vitality of hog 
cholera bacteria in the soil. This becomes infected during epizdoties 
of this disease by the discharges of the sick perhaps more thoroughly 
than anything else in the surroundings of the animals. Moreover, it 
is the most difficult to disinfect, as we have no knowledge of the 
depths to which the living virus may be carried by water. If it can 
be shown that the life of such virus in the soil is speedily destroyed, 
the precautions to be taken would be quite different from those needed 
if the virus exists for a long period of time. 
The experiments undertaken to solve this question are not com- 
pleted, but the results thus far obtained are sufficiently definite to 
warrant publication. A more detailed account will be given in the 
forthcoming report of the Bureau. 
A small flower-pot containing soil was sterilized by moist heat and 
protected from drying and dust by a large bell jar. On its surface 
about 100° of a bouillon peptone culture of hog cholera bacteria was 
poured and the whole maintained moist and at the laboratory tem- 
perature. (The soil used was a very fine loam from the grounds of 
the Department of Agriculture. 
Roll cultures from the soil after a few days showed immense num- 
bers of bacteria, From this soil rabbits were inoculated from time 
to time by stirring up a little soil in some sterile beef infusion and 
injecting the clear supernatant liquid hypodermically. The soil was 
infected September 17, 1887. The appended table gives the inocula- 
tions into rabbits to test the virulence of the soil. The rabbits which 
we 
a 
