260 
IOWA ACADEMY OF SCIENCES. 
leone’s observations. 
No. of Micro-organisms 
in one CC. of water. 
Water at time of collection contained 5 
Water after standing twenty-four hours in sterilizedjlask 100 
Water after standing two days in sterilized flask 10 , 500 
Water after standing three days in sterilized flask 67,000 
Water after standing four days in sterilized flask 315,000 
Water after standing five days in sterilized flask . More than one-half million 
cramer’s observations. 
Hours and days during which Number of Micro-organisms 
the water was preserved. in one CC. of water. 
0 hours 143 
24 hours 12,457 
3 days.... 328,543 
8 days 233,452 
17 days 17,436 
70 days 2, 500 
The work along these lines on the college sewage may 
be said to have just begun, and future experiments and 
data will materially assist in the intelligent interpretation 
of the results obtained during the last year. 
BIBLIOGRAPHY. 
1. Abbott, A. C.— 
The Principles of Bacteriology £43.96 1897 
2. Adams. Julius W — 
Sewage and Drains for Populous Districts 228.53 1889 
3. Barwise, Sidney — 
The Purification of Sewage 150 13 1899 
4. Billet, Albert — 
La Morphologie etdu Developpement des Bacteriacees...289 14 1890 
5 . Baker, M. N. and Rafter, G. W.— 
Sewage Disposal of the United States 598.7. 116 1893 
6 . Burton, W. K — 
Water Supply of Towns 304.257 1894 
7. Clark, D W. and Dempsey, G D.— 
Drainage of Lands, Towns and Buildings 351.115 1890 
8 . Davis, Flo\d— 
Report of Investigation of the Marshalltown Water Supply. .Paper 
9. Dempsey, G. D and Clark, D. K. — 
Drainage of Lands, Towns and Buildings 351.115 1890 
10. Folwell, A. Prescott — 
Sewage, the Designing, Construction and Maintenance of Sew- 
age Systems 372.12. f36. 1899 
11 . Frankland, Pei cy and C C. — 
Microorganisms in Water 
12. Gerhard, P. W. — 
Drainage and Sewage of Buildings 302 97 1894 
13. Iowa, Report of the State Board of Health '. .591 30 1889 
14. Iowa, Report of the State Board of Health 1899 
