1880.] 



MICKOSCOPICAL JOURNAL. 



187 



flueiice of water as food, particularly 

 in relation to its fauna and flora. In 

 order to study the subject it is neces- 

 sary to make microscopical examin- 

 ations, and these have been, as far 

 as I know, conlined to the water 

 drawn from the hydrant or faucet. 

 It has been supposed that these 

 forms of life have come from the 

 deeper portions of the lakes, and 

 that the central, surface waters of 

 the lakes were comparatively free 

 from them. In order to set the 

 matter at rest, in my own mind, I 

 have made examinations of the cen- 

 tral, surface waters of Cochituate 

 lake, Crystal lake, Wakefield, Mass., 

 Horn Pond, Woburn, Long Pond, 

 Shiverick's Pond, Fresh Pond, Fal- 

 mouth, Mass., Jamaica Pond, Frog 

 Pond, and the pond in the Public 

 Garden, Boston. In all these cases 

 the evidence obtained has been posi- 

 tive and decisive, so that I think it 

 is of value as showing that the bo- 

 tany and zocilogy of the central sur- 

 face waters of these lakes is repres- 

 ented by a large number of species for 

 microscojiical examination ; indeed 

 the waters of Frog Pond, on Boston 

 Common, is a mine of specimens 

 for a microscopist. 



Now, my object in this conmmni- 

 cation is to call attention to this 

 subject with the view that if I am 

 mistaken in its novelty, I may be 

 corrected, and if not, to invoke those 

 in different parts of the country who 

 may be so disposed, to make exam- 

 inations of the various surface wa- 

 ters of the ponds in their vicinity, 

 that are used for drinking purposes, 

 and report to this journal, so that 

 one can get an idea of the subject 

 based on extensive examinations, 

 conducted by a large number of ob- 

 servers in different parts of the 

 country. When this is done, it will 

 be a help to the physican who stu- 

 dies water as food. 



Perhaps it may be proper for me 



to allude to my own methods of col- 

 lection. I go out in a boat to the 

 central part of the pond, provided 

 with a tumbler or dipper, a three- 

 quarter inch India-rubber tube, an 

 old lawn hose-pipe a foot long, with 

 a bag four and a half inches long by 

 two and three-quarters of an inch 

 in width, made of the best cotton 

 cloth, tied on the end of the tube. 

 I then pour water into the tube 

 with the tumbler or dipper until the 

 water begins to sink slowly, then I 

 stop pouring and let the water run 

 off until its surface can be seen 

 through the walls of the bag; the 

 string is untied, the bag removed 

 and its contents suddenly poured 

 into the empty tumbler or dipper ; 

 the bag is then gently turned inside 

 out and gently sopped in the water 

 which has beed poured into the tum- 

 bler. Having done this, I begin to 

 twist the bag from above down- 

 wards, and allow the drip to run 

 into the tumbler or dipper. This 

 is a modification of Prof. Reinsch's 

 process, with whom I have studied. 

 For a microscope, I have found 

 my horizontal tube Amici, and a 

 one and a half inch eye-piece and a 

 Tolles, third class,one-fif th objective, 

 with a low angle and long working 

 distance, to be satisfactory. I find 

 a brass cell, such as formerly came 

 with the French microscopes,t wo and 

 one-half by seven-eighths inch, and 

 three-eighths of an inch deep, with 

 a glass bottom, to answer very well, 

 only instead of using the deep ca- 

 vity, I reverse the cell and employ 

 the shallow cavity. This method 

 may not be liked by some, but I 

 like it, as I have room, and examine 

 the plants uncovered and free. The 

 tremulous motion of such a body of 

 liquid is an objection, but barring 

 this, I find that I get a more tho- 

 rough knowledge of the character 

 of the water than in any other mode 

 I am acquainted with. T find this 



