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IOWA ACADEMY OF SCIENCE Voi.. XXVII, 1920 
representative on the staff of the Water Supply Officer for the 
Army. The laboratories employed for the work of the Water 
Supply Service were usually operated more or less independently 
as sections of Medical Department laboratories to which the Water 
Supply personnel was attached for purpose of administration 
and supply. Of course, additional water analysis was carried out 
by the regular Medical Department laboratories, sometimes in 
cooperation with the Water Supply Laboratories, sometimes inde- 
pendently. 
For special work in the advance zones the laboratory work was 
conducted in mobile laboratories, in the laboratory space of the 
‘‘sterilab” water purification trucks and with transportable labora- 
tories supplied in chests. 
The methods of water analysis were based chiefly upon the 
Standard Methods of Water Analysis of the American Public 
Health Association, 1917, and Medical War Manual No. 6, Lab- 
oratory Methods of the U. S. Army, 1918. The standard of 
purity adopted was the 1914 standard of the United States 
Treasury Department for drinking water supplied by common 
