PREVIOUS REPORTS UPON TYPHOID FEVER. 
225 
RELATIVE MERITS OF SLOW SAND AND MECHANICAL FILTRA- 
TION.a 
This document contains a report by Dr. Samuel C. Busey, Dr. G. 
Wythe Cook, Dr. George M. Kober, Dr. Z. T. Sowers, and Dr. William 
C. Woodward, a committee of the Medical vSociety of the District of 
Columbia, upon the relative merits of slow sand filtration and mechan- 
ical filtration with special application to the problem in Washington. 
After comparison of the two systems the installation of slow sand 
filtration is urgently recommended. 
THE RELATIVE MERITS OF THE MECHANICAL AND THE SLOW 
SAND SYSTEMS OF FILTRATION FOR THE WATER SUPPLY OF 
THE DISTRICT OF COLUMBIA. & 
This document contains a report by Messrs. Rudolph Hering, 
George W. Fuller, and Allen Hazen. In consideration of the full 
evidence they recommend the construction of a complete system of 
slow sand filters with such auxilliary works as may be necessary for 
preliminary sedimentation and the use of a coagulant for a part of 
the time. There is no reason to believe that the use of this coagulant 
will in any degree affect the wholesomeness of the water. 
PURIFICATION OF THE WASHINGTON WATER SUPPLY, c 
This document contains a discussion upon sand filtration in rela- 
tion to typhoid fever with special reference to the comparative 
merits of slow sand filtration of the English system and mechanical 
filtration with coagulation known as the American system. Those 
who took part' in the discussion were Messrs. Rudolph Hering, 
George W. Fuller, Allen Hazen, J. M. Diven, E. B. Weston, John W. 
Hill, George A. Johnson, Dr. J. S. Billings, and Prof. William P. 
Mason. 
This document also contains letters from Dr. H. D. Geddings, of 
. the Marine-Hospital Service, Lieut. Col. Charles Smart, U. S. Army, 
and Mr. Robert Spurr Weston upon the filtration of public water 
supplies with special reference to the Potomac River. There is also 
an extract from the report of the committee on the public health of 
the Washington Board of Health and other historical and documen- 
tary matter bearing upon the subject. 
® Report made by a special committee of the Medical Society of the District of 
Columbia upon the relative merits of slow sand and mechanical filtration. 56th Cong., 
2d sess, S. Doc. No. 27. [December, 1900.] 
56th Cong., 2d sess., S. Rept. No. 2380. [February, 1901.] 
c An inquiry held by direction of the United States Senate Committee on the Dis- 
trict of Columbia. Edited and compiled by Charles Moore, clerk of the Senate Com- 
mittee on the District of Columbia. Washington, Government Printing Office [Feb- 
ruary 19], 1901. 56th Cong., 2d sess., S. Rept. No. 2380. 
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