128 THE AMERICAN MONTHLY [May, 



About seven years ago the author became satisfied that the mi- 

 croscope was capable of yielding a large amount of useful infor- 

 mation in regard to the natural history of water supplies, and, 

 in pursuance of this view, began a somewhat extensive study of 

 the biologv of the water supply of the city of Rochester. At 

 that time, aside from some work done by Mr. Vorce at Cleve- 

 land, and by Prof. Kellicut and Mr. Mills at Buffalo, almost 

 nothing had been done in the way of systematic study of all the 

 forms present in public water supplies. * The observations of 

 these gentlemen may be found recorded in the proceedings of the 

 American Microscopical Society, and it is therefore unnecessary 

 to further refer to them at this time, except to say that some of 

 their generalizations as to (i) the permanency of certain forms 

 at all seasons of the year, and (2) as to the actual quantity of mi- 

 croscopical life in Lake Erie water, are of interest and value, and 

 have largely furnished the incentive for more extended observa- 

 tions on the part of the author. 



A few months' study was sufficient to show that the task under- 

 taken was a very large one, and accordingly, in May, 18S6, the 

 author presented a paper to the Microscopical vSection of the 

 Rochester Academy of Science, in which it was suggested that 

 the Section take up the systematic study of the Hemlock Lake 

 water supply of the city.f This was followed by a second paper 

 in December of the same year, t with the result that finally the 

 Section undertook the proposed study, continuing without inter- 

 ruption for nearly three years. To Major William Streeter, Drs. 

 M. L. Mallory and J. Edw. Line, Mr. A. L. Dumond, and other 

 members of the Microscopical Section of the Rochester Academy 

 of Science, the success of the work was very largely due ; and 

 while the present writer, by reason of mostly being the author of 

 the various papers put forth, has received the greater portion of 

 whatever credit attaches to the work, it is nevertheless just that 

 the gentlemen in question should receive recognition as joint 

 participants with the author in what has apparently turned out to 

 be on the whole an exceedingly useful study in new fields. In 

 making this special acknowledgment, the author further takes 

 occasion to say that he hopes any other person beginning similar 

 studies may be blessed by the counsel of such tried friends as 

 those whose services are here gratefully acknowledged. 



The work included (i) weekly examination of samples of 



* The writer does not overlook the early work of Prof. John Torrey on the Croton, or Prof. 

 Horsford and others at Boston, or the more recent work at Boston of Professors Farlow, Rem- 

 sen, Hyatt, Mr. Burgess, Mr. Fteley and others, and of Prof. Lattimore at Rochester, etc. 

 These, however, were all comparativriy short studies undertaken for a special purpose and soon 

 discontinued. The work of Messrs. Vorce, Kellicut, and Mills, therefore, stood almost alone 

 as systematic attempts to determine by microscopical methods the sanitary significance of the 

 vast number of minute forms found in even very pure waters, and, as such, deserves special 

 attention in a historical notice of this kind. 



t On the Use of the Microscope in Determining the Sanitary Value of Potable Water, with 

 Special Reference to a Study of the Biologv of the Water of Hemlock Lake. Proc. Micr. Sec. 

 Roch. Acad.Sci., 1886. By Geo. W. Rafter. 



+ How to Study the Bioh.gy of a Water Supply. Proc Micr. Sec Roch. Acad. Sci., 1887. 

 By Geo. W. Ralter. 



