128 THK AMKIUCAN MONTHLY [May, 



About seven voars a«;c) the author became sati.sHed that llie mi- 

 croscope was capable of viehliui; a larji^e amount of useful infor- 

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

 in pursuance of this view, bejjan a somewhat extensive stutly of 

 the biolo<;v o( the water supply of the city of Rochester. At 

 that time, aside tVom some work done by Mr. \'orce at Cleve- 

 land, and by Prof". Kellicut and Mr. Mills at BulValo, 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 ma\ be fouiul recorded in the proceedings t)f the 

 American Microscopical Society, and it is therefore unnecessary 

 tt> 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 vear, and (2) as to the actual quantity of mi- 

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

 have largciv furnished the incentive for more extended observa- 

 tions on the part of the author. 



A few months' studv was sutHcient to show that the task under- 

 taken was a very large one, and accordingly, in May, 1SS6, the 

 author presented a paper to the Microscopical Section of the 

 Rochester Academv of Science, in which it was suggested that 

 the Section take uji the systematic study of the Hemlock Lake 

 water suppiv of tlie city.t This was followed by a second paper 

 in Decemlier of the same vear,J with the result that linally the 

 Section undertook the proposed study, continuing without inter- 

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

 ^L L. Mallory and J. E<lw. 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, bv 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 exceedinglv 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 mav 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 docs not overlook the early work of Prof. John Torrcy on the Croton, or Prof. 



Horsford and others at Boston, or the more recent work at Ho-iton of Professors Farlow, Kem- 



»en, Hyatt, Mr Burgess, Mr. Ktelcy and others, and ot Prof Lattimorc at Rochester, etc. 



I h.-.' K .ui-.ver. were all comparatively short siiiHics undertaken for a special purpose and soon 



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



attempts to determine by microscopical methods the sanitary significance of the 



.- jf minute forms found in even very p.ire 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 th; Biology of the W n. r of Hemlock Lake. Proc. .Micr. Sec. 

 Roch. Acad Sci , 1886 BvGeo W. Rafter. 



: How to Study the yiiuUr^y ol a SV.iter supply. . S'^c Roch. /Vcad. Set., 1807. 



By Ceo. \V k..lter 



