34 ROCHESTER ACADEMY OF SCIENCE. [ March 10, 
The Council report recommended, 
(1) The payment of certain bills. 
(2.) The election of Hon. M. W. Cook and Prof. Henry A. Ward 
as active members. 
(3.) The adoption of a resolution in substance authorizing the 
Corresponding Secretary to purchase books for the Academy, not to 
exceed in amount five hundred dollars, and to himself advance the 
money, holding the books as security. 
The items of the report were adopted, and the nominees elected 
by tormal ballot. 
The following resolution offered by Supt. S. A. Ellis was adopted : 
Resolved: That Mr. Henry C. Maine who has been connected 
with the Academy from its foundation, and who was for some time its 
Secretary, be requested to prepare a brief history of the Academy from 
its foundation to the time of the late reorganization. 
The following paper was read : 
BIOLOGICAL EXAMINATION OF POTABLE WATER, 
By GEorGE W. RAFTER. 
The biological examination of water requires the determination of 
all the minute life occurring in various classes of water, and is divided 
into two distinct investigations, the microscopical and the bacterial. 
The microscopical examination includes the determination of all those 
forms of life which are easily studied in all their phases by use of the 
microscope. These forms include among plants, alge, larger fungi, 
etc., and among animals, sponges, infusoria, rotifers, the smaller 
crustacea and others. 
The bacterial examination requires cultures as an integral part of 
the process, and only incidentally makes use of the microscope, inasmuch 
as examinations and partial identifications may be made from plate and 
tube cultures without the use of the microscope at all. 
The methods of making bacterial examinations have been fairly 
worked out for several years, but until recently no definite method of 
making the accurate determination of the number of the so-called 
microscopic forms has been known. 
The present paper includes the microscopical examination only, 
and the methods here indicated have no reference to the bacteria. 
Something over three years ago the Microscopical Section of this 
Academy began a systematic study of the forms of minute life present 
in the Hemlock lake water supply of this city. The method of 
