tifically investigated. In this
investigation one fact after another was discovered and confirmed;
some of these facts seemed to give clearer conceptions of the disease,
others served to make it more obscure; new questions arose with each
extension of knowledge; in the course of the work new methods of
investigation were discovered; the sides of the arch were slowly and
painfully erected by the work of many men, and finally one man placed
the keystone and anthrax was for a long time the best known of
diseases. Men whose reputation is now worldwide first became known by
their work in this disease. It was a favorable disease for
investigation, being a disease primarily of cattle, but occasionally
appearing in man, and the susceptibility of laboratory animals made
possible experimental study.

Anthrax is a disease of domestic cattle affecting particularly bovine
cattle, horses and sheep, swine more rarely. The disease exists in
practically all countries and has caused great economic losses. There
are no characteristic symptoms of the disease; the affected cattle
have high fever, refuse to eat, their pulse and respiration are rapid,
they become progressively weaker, unable to walk and finally fall. The
disease lasts a variable time; in the most acute cases animals may die
in less than twenty-four hours, or the disease may last ten or
fourteen days; recovery from the disease is rare and treatment has no
effect. It does not appear in the form of epidemics, but single cases
appear frequently or rarely, and there is seemingly no extension from
case to case, animals in adjoining stalls to the sick are not more
prone to infection than others of the herd. On examination after death
the blood is dark and fluid, the spleen is greatly enlarged (one of
the names of the disease "splenic fever" indicates the relation to the
spleen) and there is often bloody fluid in the tissues.

Where the disease is prevalent there are numbers of human cases. Only
those become infected who come into close relations with cattle, the
infection most commonly taking place from small wounds or scratches
made in skinning dead cattle or in handling hides. The wool of sheep
who die of the disease finds its way into commerce, and those employed
in handling the wool have a form of anthrax known as wool-sorters'
disease in which lesions are found in the lungs, the organisms being
mingled with the wool dust and inspired. In Boston occasional cases of
anthrax app