258 



SCIENCE. 



[N. S. Vol. XXI. No. 529. 



methods, but give varying results, depend- 

 ing on the niodifieation used. 



AVe are able to make a rough comparison 

 between the results obtained by the English 

 methods, with those obtained by the modi- 

 fications of Kubel's process, and compare 

 with each other the results obtained by the 

 four modifications of Kubel's process. To 

 compare results obtained by the English 

 methods with Palmer's modifications of 

 Kubel's process, thirty minutes at 100° C, 

 with potable watere multiply the former 

 by two and one half; to compare with 

 American Association for the Advancement 

 of Science method ten minutes at 100° C, 

 potable waters multiply by two, with 

 sewage multiply by four; to compare with 

 Public Health Association method, five 

 minutes at 100° C, with potable waters no 

 change, with sewage multiply by two and 

 a quarter; to compare with Massachusetts 

 State Board of Health method, two 

 minutes at 100° C, with potable waters no 

 change, with sewage multiply by two. 



To compare in the same way with each 

 other the results obtained by the modifica- 

 tions of Kubel's process the following table 

 can be used, taking the results obtained by 

 the M. S. B. H. method as unity. 



M.S.B.H. A.P.H. A.A.A.S. Palmer's 

 Potable waters.. 1 1.25 1.75 2 

 Sewage 1 1.50 2 2.50 



ISUnidard Methuds to he used in tlce Sani- 

 tary Analysis of Water: L. P. Kinni- 



CUTT. 



A paper showing that the results ob- 

 tained in the sanitary analysis of water 

 depend to a large extent on the method of 

 procedure by which the various determina- 

 tions are made, and that at the present 

 time there is no conformity among chem- 

 ists as to the method of procedure. A 

 variation of one hundred per cent, in cer- 

 tain determinations, depending on the 

 process used, is not uncommon. The only 

 way of obtaining results which shall be 



comparable is to follow the lead of the 

 official agricultural chemists of this coun- 

 try and adopt standard methods to be used 

 in the analyses of potable waters and 

 sewage. 



Determination of Nitrites in Water: R. S. 

 Weston. 



Biochemistry of Sewage Purification, the 

 Bacteriolysis of Peptones and Nitrates: 

 S. D. Gage. 



In the treatment of sewage by modern 

 biological methods, a great variety of chem- 

 ical reactions occur, all of which are caused 

 directly or indirectly by the action of bac- 

 teria. It was shown that bacteria common 

 in sewage disposal are able to produce am- 

 monia from organic matter, to reduce 

 nitrates to nitrites, to ammonia and prob- 

 ably to elementary nitrogen, to liberate 

 nitrogen from solutions of organic matter 

 and also to fix atmospheric nitrogen, ilany 

 sewage bacteria also probably produce the 

 lower oxides of nitrogen as reduction pro- 

 ducts of nitrates, which oxides may play an 

 important part in the further decomposi- 

 tion of the organic matter in solution either 

 through catalytic action or by direct chem- 

 ical reaction. The amount of ammonia 

 and the amount of nitrates reduced vary 

 widely with different classes of bacteria, as 

 does also the character of the reduction 

 products of the nitrates. It has been found 

 that a majority of the bacteria common in 

 sewage and in sewage disposal systems re- 

 duce nitrates and form ammonia from or- 

 ganic matter, although these two functions 

 are not always synonymous with the same 

 species. Furthermore, it was found that 

 there was a close relation between the 

 ability of bacteria to peptonize insoluble 

 organic matter and the ability to reduce 

 nitrates and to ammonify this organic mat- 

 ter, although many exceptions have been 

 noted to this rule. 



The paper will be published in the 

 Journal of the society. 



