It may justifiably be said that no other sanitary measure has accomplished so much at so small a cost; and that civilization owes a deep debt of gratitude to the pioneers in municipal water chlorination: Dr. A. C. Houston in England, and Mr. G. A. Johnson and Dr. Leal in America.

In this volume I have endeavoured to collect and correlate the information hitherto scattered in various journals and treatises and to present it in a comprehensible manner. The various aspects and methods of chlorination are discussed and suggestions have been made which, I hope, will stimulate research work in this fertile field of science.

I wish to acknowledge my indebtedness to the engineering staff of the Ottawa Water Works Department and to Lieut. W. M. Bryce for the preparation of diagrams.

Joseph Race.

Ottawa, Ont.,
April, 1918.

CONTENTS

CHAPTERPAGE
[I.][Historical][1]
[Sodium Chloride.] [Chlorine.] [Bleach.][Eau de Javelle.] [Antiseptics.] [Hermite fluid.][Webster’s process.] [Electrozone.][Chlorination of sewage in Germany, U. S. A.,and England.] [Chlorination of water.] [Lincoln installation.][Oxychloride.] [German experiments.] [Europeanpractice.] [Inception of chlorination in America.]
[II.][Modus Operandi][14]
[Composition of bleach.] [Bleaching action.] [Nascentoxygen hypothesis.] [Hydrolysis of bleach.] [Effect of acidsand salts on hydrolysis and germicidal action.] [Effect ofammonia.] [Direct toxic action.] [Hypochlorous acid.][Sodium hypochlorite.] [Chlorine water.] [Nature of action.]
[III.][Dosage][30]
[Organic matter.] [Initial count.] [Viabilityof organisms.] [Mineral matter.] [Colour.] [Temperature.][Admixture.] [Contact period.] [Turbidity.] [Light.][Determination of dosage.]
[IV.][Bacteria Surviving Chlorination][50]
[Disinfectants.] [Antiseptics.] [Viability ofbacteria.] [New York results.] [Reversed ratio of counts.] [Coliformorganisms.] [Aftergrowths in water and sand.]
[V.][Complaints][62]
[Auto-suggestion.] [Tastes and odours.] [Sludge problem.][Colic.] [Effect on fish and birds.] [Effect on plants andflowers.] [Corrosion of iron and lead pipes.]
[VI.][Bleach Treatment][72]
[Storage of bleach.] [Mixing tanks.] [Storage tanks.][Dosing apparatus.] [Control.] [Analysis of liquor.] [Detection and estimation of free chlorine.] [Chlorometer.] [Cost ofconstruction and operation.] [Antichlors.] [DeChlor filters.]
[VII.][Liquid Chlorine][89]
[Historical.] [Leavitt-Jackson machine.] [Electro BleachingGas Co.’s types.] [Wallace and Tiernan’s manual controltypes.] [Effect of temperature on gas pressure.] [Impuritiesin gas.] [Advantages.] [Comparison of liquidchlorine and bleach.] [Cost of treatment.] [Popularity.][Chlorine water.]
[VIII.][Electrolytic Hypochlorites and Chlorine][105]
[Hermite fluid.] [Eau de Javelle.] [Chloros.][Non-diaphragm cells: Dayton, Hermite, Mather and Platt, Haasand Oettel.] [Diaphragm cells: Hargreaves-Bird, Nelson,Allen-Moore.] [Montreal installation.] [Costs.]
[IX.][Chloramine][115]
[Preparation.] [Absorption by water.] [Experimentalresults.] [Works results.] [Ratio of chlorine to ammonia.][Economics.] [Advantages.] [Operation.] [Otherchloramines.] [Halazone.]
[X.][Results Obtained][132]
[Object of chlorination.] [Effect on filter rates and algæ.][Hygienic results.] [Typhoid rates.] [Typhoid reduction atPhiladelphia, Chicago, and Ottawa.] [Abortive epidemics.][Use and abuse of chlorination.]
[Appendix][147]
[Estimation of free chlorine in water.]
[Name Index][151]
[Subject Index][155]