September 25, 1914] 



SCIENCE 



449 



(rather than as a source of fish food) is a sub- 

 ject of American origin and development. It 

 was bom in the laboratories of the Massachu- 

 setts Institute of Technology, nurtured by the 

 Massachusetts State Board of Health and the 

 Boston Water Board, and brought to full ma- 

 turity in the Mt. Prospect Laboratory of the 

 Water Department of Brooklyn. In Boston 

 and in Brooklyn Professor Whipple was the 

 leading spirit in the investigation of this sub- 

 ject. 



His admirable book on the " Microscopy of 

 Drinking Water " was first published in 1899 

 and has remained the standard text upon this 

 subject. A third edition comprehensively re- 

 written to include the experience of the last 

 fifteen years is most welcome to all workers in 

 this fascinating and practically important 

 field. 



The main objects of the miscroscopical 

 study of water are of course first to determine 

 the causes of odors and turbidities in water 

 and to control the remedial measures applied 

 to them, and second, to work out the relation 

 of the plankton to the life of fishes. It is also 

 of value in certain cases as an index of sew- 

 age contamination, as a measure of the proc- 

 esses of seK-purifieation of streams, as an ex- 

 planation of the sanitary chemical analysis, 

 and as a means of identifying water from par- 

 ticular sources. Professor Whipple is doubt- 

 less correct in his conviction that " the microl- 

 ogy of water is going to play an increasingly 

 important part in the science of sanitation." 



The methods used for the microscopical ex- 

 amination of water remain essentially as they 

 were worked out by Professor W. T. Sedg- 

 wick and Mr. George W. Eafter in 1889. 

 Three important modifications are, however, 

 described by Professor Whipple, the sling filter 

 for examinations in the field, the use of a 

 round cell for counting instead of the expen- 

 sive and cumbrous oblong one and the use of 

 the cotton disc filter which gives an admir- 

 able general idea of the total amount of plank- 

 ton in a given water. A new chapter on the 

 microscope and its uses by Dr. J. W. M. 

 Bunker is added to the discussion of the spe- 

 cific methods used in water examination. 



Professor Whipple's discussion of limnology 

 is extended and amplified in many respects, 

 particularly in regard to the estimation of dis- 

 solved gases and their effect upon plankton 

 growth. In general the effect of various en- 

 vironmental conditions upon the multiplica- 

 tion of water organisms is admirably dis- 

 cussed. The diagram of plankton changes in 

 the Genesee River is particularly striking, 

 showing the rise first of bacteria, then of pro- 

 tozoa, then of rotifers and Crustacea, as each 

 group preys upon the preceding one. The re- 

 viewer must demur at one conclusion, drawn 

 on page 215, to the effect that a curve show- 

 ing seasonal variations of blue-green algse and 

 bacteria in Baiseley's Pond, indicates that the 

 former are antagonistic to the latter. It is 

 quite true that the bacteria increase in spring 

 and fall and the cyanophytes in summer; but 

 it seems more probable that the increase in 

 bacteria is merely the usual fall and spring in- 

 crease due to rains and thaws, which occurs in 

 all surface waters, than that the cyanophytes 

 have anything to do with it. The season of 

 the year has a great many effects upon a great 

 many things and plotting two effects against 

 each other as if they were related has led to 

 many errors. 



The most important additions to Professor 

 Whipple's book relate to the practical control 

 of the growths of microscopic organisms and 

 the obnoxious odors and turbidities which they 

 produce. This subject was in its infancy fif- 

 teen years ago, but to-day there are three well 

 recognized preventive or remedial procedures, 

 stripping of the reservoir site, treatment with 

 copper sulphate and aeration. Stripping of 

 the reservoir of its organic soil to eliminate 

 the food of the microorganisms has been ex- 

 tensively used in Massachusetts, but the re- 

 port of Messrs. Hazen and Fuller in connec- 

 tion with the proposed application of this 

 method to the New York water supply (from 

 which Professor Whipple quotes extensively) 

 leads to the conclusion that stripping can not 

 by itself be expected to produce satisfactory 

 results and in most cases involves a large ex- 

 pense of doubtful value. The destruction of 

 the microorganisms by treating reservoir 



