Jtot 17, 1914] 



SCIENCE 



111 



ist3 may be compared and the error of analysis 

 may not be concealed. As the order of maJdng 

 hypothetical combinations is purely conventional 

 the author strongly urged that no scheme of ma- 

 king such combinations be included in the report 

 of the Committee on Standard Methods of Water 

 Analysis but that the data of the analysis be re- 

 ported in ionic form. 



New Apparatus for the Determination of Hydro- 

 gen Sulfide in Water: Geoege B. Frankfoktee. 



Sanitary Survey of the Ohio River hy the V. S. 

 Public Health Service: W. H. Pkost and H. W. 

 Streetee. 



The Use of Liquid Chlorine in Treating the Water 

 Supply of Indian<L Harbor, Ind.: H. K. Jordan. 



The Adaptation to Water Analysis of the Determi- 

 nation of Potassium as the Perchlorate: CIiAK- 



ENCE SCHOLL. 



A detail comparison of the platinic chloride and 

 perchlorate methods of determining potassium is 

 given. The cost of the latter is about 0.7 per cent, 

 of the former. The ease in manipulation is also 

 much greater in the perchlorate method. The re- 

 sults obtained are accurate. The perchlorate 

 method is then given in detail. The sulphate and 

 ammonium ions and all volatile acids must be re- 

 moved. The residue is evaporated to dryness with 

 perchlorate acid imtil all the salts are perehlorates. 

 The perchlorate salts of aU. the common elements 

 except potassium are soluble in 96 per cent, to 97 

 per cent, alcohol containing 0.2 per cent. HClOj, 

 The potassium perchlorate obtained is weighed in 

 Gooch crucibles after drying one hour at 120°— 

 130°. The method was used on many waters con- 

 taining known amounts of potassixmi. The errors 

 are small. The phosphate radicle has no effect on 

 the determination. The perchloric acid is now 

 available to every chemist. The method can be 

 recommended for use in water analysis and prob- 

 ably for all other analytical work where the con- 

 tent of potassium is desired. 



The Preparation of Standards for the Determina- 

 tion of Turbidity of Water: Feancis T>. West. 



Report of the Com/mittee on Standard Methods of 

 Water and Sewage Analysis. 



Chemical Studies of the Pollution of the Ohio 



Biver: Eaele B. Phelps. 



The investigation of the Ohio Eiver now being 

 conducted by the XT. S. Public Health Service 

 under the direction of Passed Assistant Surgeon 

 Wade H. Frost has for its object the determina- 

 tion of the extent and character of present pollu- 



tion, the capacity of the stream to care for this 

 and future pollution, and the effect, if any, upon 

 the public health of riparian communities. It is 

 hoped in addition to obtain data for a general dis- 

 cussion of the principles of self -purification of 

 streams. The capacity of a stream for re-aeration 

 determines its capacity to dispose of pollution. 

 The general laws of re-aeration are known but 

 their application to a stream requires the determi- 

 nation of certain constants, characteristic of each 

 stream type. 



Investigation Relating to the Vse of Calcium 

 Hypochlorite as a Disinfectant for Water Sup- 

 plies: W. G. TiCE AND C. H. BLAN CHARD. 



Some Further Results of the Hypochlorite Disin- 

 fection of the Baltimore City Water Supplies; 

 A Comparison of the Reduction of the Different 

 Members of the B. coli Group: J. Boslet 

 Thomas and Edgae A. Sandman. 

 The hypochlorite treatment of the Baltimore 

 city water supplies was instituted in June, 1911, 

 pending the erection of a filtration plant. In one 

 supply the hypochlorite was added at the im- 

 pounding reservoir; in the other supply, consti- 

 tuting about three fourths of the consumption, it 

 was found feasible to apply the disinfectant at 

 the effluent of the first storage reservoir, after the 

 water had received a preliminary treatment with 

 aluminum sulfate. The treatment effected a re- 

 duction of 99 per cent, of the organisms growing 

 at 20° C. in the sedimented water of one supply, 

 and 83 per cent, in the other supply, where no 

 coagulant was added previous to the disinfectant. 

 The reductions in the numbers of organisms grow- 

 ing at 37° C. were 85 per cent, and 76 per cent, 

 respectively. There was but little difference in the 

 relative reductions of the members of the B. coli 

 group, these reductions being between 97 and 99 

 I)er cent., based upon about fifteen hundred iso- 

 lations. The number of eases of typhoid fever 

 occurring in Baltimore during 1913 was seventeen 

 per cent, less than an average of the number of 

 cases occurring during the five years from 1906 

 to 1910 before the treatment was instituted. 



Filtration and Softening of the Cleveland Water 



Supply: HiPPOLTTE Getjenee. 



The Cleveland water situation is marked by a 

 comparatively high grade of raw water, both as 

 respects its hardness and bacterial content. The 

 increase of the typhoid rate resulted in 1911 in the 

 use of bleaching powder. Popular objections to 

 this combined with the conditions after the flood 

 of 1913 led to the decision to filter. The rapid 



