METEOROLOGY — WATER. 739 



Water supply and sewerage i Ann. Rpl. Bd. Health Mass. ,86 I 1904 I, pp. / -"' • I. 

 This is tin- annual reporl of tin* State board <>f Health to the legislature, and 

 includes accounts of advice to cities and towns regarding water supply, ice supplies, 

 sewerage and sewage disposal, and pollution of ponds and strean s; examination of 

 water supplies; examination of rivers; water-supply statistics; and experiments od 

 the filtration and purification of sewage and water a1 the Lawrence Experimenl Sta- 

 tion in 1904. 



Examinations with reference to free and albuminoid ammonia, nitrates and nitrites, 

 oxygen consumed, hardness, suspended matter, residue on evaporation, color, and 

 (•dor are reported for a large number of samples of water from the water supplies of 

 various Massachussetts town-, as well as similar data for water of various streams in 

 the state. Data are also given showing the relation of rainfall to How of Btreams. 



The reports on experiments in purification of sewage present a large amount of 

 data bearing on the storage of nitrogen in and removal from filters; nil rogen-disposal 

 efficiency; lossof nitrogen in case of different kinds of filters; the relation of bacteria 

 to the operation of filters and to sewage purification in general; and the bacteria in 

 septic sewage and in the effluents from filters operated with septic sewage ( E. 8. B 

 17. p. 300). 



The more important conclusions reached arc as follows: 



" | I i With new sand filters a smaller percentage of the applied nitrogen appears 

 in the effluent than when the filters have been operated for a considerable period. 



With filters producing eminently satisfactory purification . . . the average 

 amount of nitrogen appearing in the effluents as nitrates is but little more than 50 

 per cent of the nitrogen in the applied sewage. 



" (."») This being so, it is clear that, if a filter is not ultimately clogged by stored 

 nitrogenous organic matter, either removal of this matter must be resorted to, 

 together with a removal of some of the filtering material, or a removal by bacterial 

 actions independent of and differing from those of nitrification must be depended 

 upon. 



" (4) Much of the increase of unoxidized nitrogen in the effluent of the sand filters 

 has been due to the increase of applied nitrogen year by year and the accumulation 

 of stable organic matter in the filter. 



"On account of the application of this larger amount of nitrogen two results ensue: 

 (1 i An amount of nitrogen in solution greater than can be easily and completely 

 changed by bacterial action during the period of passage of the sewage through the 

 filter, and (2) an amount of stable organic matter in suspension in the sewage is 

 Strained out, and, accumulating in the upper sand of each filter, causes unfavorable 

 conditions, especially in winter, on account of the resultant increased compactness 

 of t hese upper layers. 



"Differing bacterial flora in the filter due to increase in stored organic matter and 

 continued use of the filter may also be an important factor." 



The use of copper sulphate at rates varying from 1 part to 1 , 130,000 parts of water 

 to 1 part to 578,000 parts of water in connection with Band filters resulted in a 

 marked decrease of bacteria in the water and in some cases in the total extermination 

 of Bacillus coli communis. Sulphate of alumina used in similar manner produced 

 like though less pronounced germicidal effects. 



The bacteria of the air, water, and soil, E. Bodin {Lea bacUries d\ Vair, dt 

 Peoti et du sol. Paris: Massm & Co.; Gauthier-ViUars [190s] } pp. 197, figs. P).— This 

 book forms one of the volumes of the EncyclopSdii scientifique des aide-mhnoin pub- 

 lished under the direction of Leaute, and summarizes the more important fact- relat- 

 ing to the bacteriology of the air, water, and soil. 



