182 
TYPHOID FEVER IN DISTRICT OF COLUMBIA. 
Viability in feces, soil, cadavers, etc. Some of the work already 
reviewed gives instances where part of the time reported as the 
observed period of longevity in water must be attributed to soil. 
Levy and Kayser (1903) report an instance of natural occurrence 
where water, excepting the moisture of rain, etc., played no part. The 
stools of a typhoid patient were placed in a cemented vault between 
September 8 and 13, 1901. As the patient was then removed to another 
locality for treatment, it is presumed that no further typhoid infection 
of the vault occurred. The contents of the vault were removed and 
placed on garden earth as manure on February 6, 1902. When this 
became known to the local physician, he took specimens of the soil on 
which the feces had lain, on February 20, and sent them to the labora- 
tory, where B. typhosus ’was recovered from them. No doubt of its 
identity exists, as it agglutinated with specific serum in a dilution of 
1-5,000. This, it will be noticed, was in winter, and the temperature 
of the soil in the vicinity varied from 0° to 4.2° C., and that of the 
atmosphere from —5.4° to -|-11.6° C. Before we accept the results 
of this case without reserve, reinfection of the soil or feces after 
February 6 must be absolutely excluded, a manifest impossibility, 
but aside from this imperfection the case is proof of the existence of 
B. typhosus in feces and soil for at least five months. 
Robertson (1898) experimented vfith soils out of doors and under 
natural conditions, except as regards inoculation, which was vdth 
bouillon culture and at various depths, after the removal of the grass. 
In one series he was able to recover the organism after one hundred 
and forty-three days, but could not do so a week later. The period 
covered was from May to October. In another series he tried to 
recover it after about three months, but failed. However, by enrich- 
ing the soil from time to time with weak beef tea or other organic mat- 
ter he succeeded in reviving the bacillus and isolated it from the same 
soil after nearly a year (eleven months). This process of organic 
enrichment is paralleled where the soil around a sink drain is con- 
tinually moistened by seepage, or where kitchen waste is thrown out 
on the ground. His method of isolation did not include enrichment 
processes, but identification was complete, so that the error, if any, was 
in the direction of shortening the period of viability. He also states 
that the bacilli inoculated at a depth of 18 inches grew to the surface, 
but that no lateral growth could be demonstrated. He shows also 
that sunlight has only a superficial effect, as the bacillus was found at 
a depth of only one-sixteenth inch in some cases. In a later report 
he expresses the opinion that the bacillus dies out in the superficial 
layers of the soil during the winter but that the deeper layers remain 
able to reinfect the surface with the advent of w^arm weather. He 
states also that the baciUus dies out quickly in grass-covered surfaces. 
Firth and Horrocks (1902) worked with blocks of earth cut from 
