178 
TYPHOID FEVEE IX DISTKICT OF C0LE^:MBIA. 
2. The container: As to its effect on the contained medium in 
influencing its temperature, chemical composition, etc. Vessels of 
certain kinds of glass affect the chemical nature of contained fluids. 
3. Exposure: (1) To light, whether sunlight, diffuse or artificial 
light; (2) to heat of various degrees; (3) to air or other gases; (4) 
to moisture, and (5) to shaking or motion. Fluctuations or inter- 
mittence of exposure are also important. 
4. The bacteria used for inoculation: (1) As to the strain used, 
whether recently isolated or not; (2) the number added relatively to 
the bidk of medium used, and (3) the amoimt of nutrient material 
added at the same time, mtentionallv or otherwise. 
5. The methods of isolation and identification used. 
6. The method of recording results. 
7. The personal equation of the experimenter. 
W have no original work to report on the longevity of B. typho- 
sus, but have attempted to ascertain what results of value have been 
obtained by others. The classical articles referred to in text-books 
and compilations too often turn out on examination to be quite value- 
less from the standpoint of to-day. 
Longevity in water . — Many of the earlier investigators of this sub- 
ject used sterilized water in order to avoid the difficulties of subse- 
quent isolation. Practically, no one cares what the viability in 
sterile water may be, as this is not foimd in nature in civilized regions. 
Many others, not only of the early, but also of recent experimenters 
either employed inadequate methods or failed to report their teclmic, 
so that their results must be thrown out ff reliable conclusions are to 
be reached. 
It might be mentioned here that quite enough instances of the 
isolation of B. typhosus from naturally uifected waters are at hand 
to prove bacteriologically its occurrence therein. They seldom 
throw much light upon the length of tune that it may remain there 
viable. The follovdng case, reported by Kubler and Xeufeld (1899), 
is of great importance in tliis connection. In 1898 they isolated B. 
t;\'phosus from a well which had been infected by wasliings from the 
chamber used by a typhoid patient. The organism was identified 
culturally and by specific agglutination and Pfeiffer’s reaction. One- 
fifth ose was pathogenic to a 300 gm. guinea pig intraperitoneally 
injected. Four weeks later they again isolated a similar organism 
from the same well, lacking only the pathogenic property for guinea- 
pigs. They were able to exclude reinfection of the well during the 
meantime, as the dejecta were carefully disinfected for three weeks 
before the first specimen was taken, and thereafter. Critically 
examined, howewer, the possibility of washings from the polluted 
ground having entered the well in the time between the examina- 
tions could not be excluded, and we can only assume from this case 
that in that often-occurring natural combination of earth and water 
