or hay which contained either the bacilli or their spores.  When a dead animal was skinned on the field, the bacilli contained in the blood escaped and became mingled with the various fluids which flowed from the body and in which they grew and developed spores.  It was shown by Pasteur that even when a carcass was buried the earthworms brought spores developed in the body to the surface and deposited them in their casts, and in this way also the fields became infected.  From such a spot of infected earth the spores could be washed by the rains over greater areas and would find opportunity to develop further and form new spores in puddles of water left on the fields, which became a culture medium by the soaking of the dead grass.  The contamination of the fields was also brought about by spreading over them the accumulations of stable manure which contained the discharges of the sick cattle.  The tendency of the disease to extend to lower-lying adjacent fields was due to the spores being washed from the upper fields to the lower by the spring freshets.  Meanwhile Pasteur had discovered that by growing the organisms at higher temperatures than the animal body, it was possible to attenuate the virulence of the bacilli so that inoculations with these produced a mild form of the disease which rendered the inoculated animals immune to the fatal disease.  The description of Pasteur’s work on the disease as given in the account of his life by his son-in-law is fascinating.

Hides and wool taken from dead animals invariably contained the spores which could pass unharmed through some of the curing processes, and were responsible for some of the cases in man.  Owing to the introduction of regulations which were based on the knowledge of the cause of the disease and the life history of the organism, together with the prophylactic inoculation devised by Pasteur, the incidence of the disease has been very greatly lessened.  Looking at the matter from the lowest point of view, the money which has been saved by the control of the disease, as shown in its decline, has been many times the cost of all the work of the investigations which made the control possible.  It is a greater satisfaction to know that many human lives have been saved, and that small farmers and shepherds have been the chief sharers in the economic benefits.  The indirect benefits, however, which have resulted from the application of the knowledge of this disease, and the methods of investigation developed here, to the study of the infections more peculiar to man, are very much greater.

FOOTNOTE:  [1] The interesting analogy between fermentation and infectious disease did not escape attention.  A clear fluid containing in solution sugar and other constituents necessary for the life of the yeast cells will remain clear provided all living things within it have been destroyed and those in the air prevented from entering.  If it be inoculated with a minute fragment of yeast culture