380 PATHOGENIC BACTERIA.

fatal issue. Meteorism and great tenderness of the abdo-
men are observed. At the autopsy a sero-fibrinous or
sero-purulent peritonitis is observed—sometimes hemor-
rhagic. There is also generally a pleurisy, either serous
or hemorrhagic. All the abdominal viscera are con-
gested. The intestine is congested—contains an abun-
dant mucous secretion. The Peyer patches are enlarged.
The spleen is enlarged, blackish, and often hemorrhagic.
In cases which are prolonged the liver is discolored. The
kidneys are congested, the adrenals filled with blood.

4 4 In such cases the bacillus can be found upon the in-
flamed serous membranes, in the inflammatory exudates,
in the spleen in large numbers, in the adrenals, the liver,
the kidneys, and sometimes in the lungs. The blood is
also infected, but to a rather less degree.

4 c In cases described as chronic, the bacillus disappears
completely in from five to twenty-four hours, and pro-
duces but one lesion, a small abscess at the point of inoc-
ulation.

" Sanarelli has observed that if some of the poisonous
products of the colon bacillus or the Proteus vulgaris be
injected into the abdominal cavity of an animal recover-
ing from a chronic case, it speedily succumbs to typical
typhoid fever."

Petruschkyl found that mice that recovered from sub-
cutaneous injections of typhoid cultures frequently suf-
fered from a more or less widespread necrosis of the skin
at the point of injection.

I experienced great difficulty in immunizing a horse to
the disease, because every injection of virulent living
organisms was followed by a necrosis equalling in size the
distended area of subcutaneous tissue.

Large quantities of filtered cultures produce symp-
toms similar to those resulting from inoculation with
the bacilli. The toxic product of the bacilli is, how-
ever, practically insoluble, and, according to the ex-
periments of Loffler and Abel and those of PfeifFer and

1 Zeitschrift fur Hygiene, Bd. xii., 1892, p. 261.