338 WATER HYGIENE 
1,000,000 cells of Bacillus typhosus and 7000 after 103 days. Alternate 
freezing and thawing were very detrimental to bacteria. Experiments 
with anthrax vegetative and spore cells indicated that the spores resisted 
for some time while the vegetative cells were rather quickly destroyed. 
The cholera vibrio is reported to have been destroyed in from 6 to 10 
days. 
TABLE XXXII 
SHOWING DURATION OF LIFE OF TYPHOID BACILLI AND COLON 
BACILLI IN ICE KEPT IN A SHED IN WINTER WEATHER 
TypsHorp Bacrut. | Coton Bacruu1. 
| 
Npmber of | of ivphod | yamberct, | “ot Colon 
Bacill in Ice. | Piting. in Ice. Living 
Before freezing. ......... .. 214,000,000 | 100 269,000,000 | 100 
Frozen 8 days...... re 145,000 .067 7,000,000 30 
Frozen 14 days....... ...... 54,000 025 5,000,000 1 85 
Frozen 22 days..........+.4- 220 0001 1,020,000 388 
Frozen 31 days. ............ 0 0 
Frozen 36 days. .......0cece] wae ce cece e [| cee eae - 10,700 .0039 
Frozen 45 days. 2.1.2.6. ce .cel cece cece ee | ocee cae 1,950 .00072 
Frozen 46 days. .......0 ccc) cece cece ne | cee eeee i 0/0 
Reudiger (1911) gives in Table XXXII data secured by him on B. 
coli and B. typhosus. From this it will be seen that 99.9 per cent of 
the B. typhi die during the first eight days. Park also found similar data. 
Jordan, Russell, and Zeit (1904) found that in filtered water B. typhi 
died rapidly. Two organisms were found-after the first day and none 
later. Hilliard et al. (1915) reported that 99 per cent of B. colt were 
destroyed by freezing in tap water for three hours. 8B. subtilis showed 
a less uniform reaction. No apparent difference was noticed by these 
investigators between alternate freezing and continued freezing. Cream 
with 30 per cent of milk fat.afforded a decided protection to the bacteria. 
Ice and Typhoid Fever. The general consensus of opinion among 
sanitarians is that icé 1s not an important epidemiological factor in the 
spread of typhoid fever. , Hutchins and Wheeler (1903) reported an ice- 
borne epidemic of typhoid fever but Hill (1910) believes their evidence to 
be inconclusive. He mentions the following characteristics of ice- 
borne epidemics’ of. typhoid fever: 
1. They should occur before June. 
2, Bulk of the cases should-be on one iceman’s route, 
