WATER SUPPLY FOR TROOPS 469 



Chloramiiie-T (sodium toluene sulphamide) , one of the Dakin 

 antiseptics, lias been tried by Mackenzie Wallace in India. The 

 aiitiseptie is very slightly soluble. Its action is very slow, al- 

 though there is a marked retardation of the aftergrowth of the 

 bacteria which usually results when the effect of the sterilizing 

 agent has worn off or a re-infection of the sterile water has taken 

 place. As much as .4 gm. of the disinfectant and ten hours' time 

 are required for the sterilization of a liter of water. Another one 

 of the chloramine group of antiseptics has been proposed by 

 Dakin and Dunham (2) under the name of "Hala^one," (para 

 sulphon di chlor amino benzoic acid ) . This is said to be effective 

 in a concentration of 1 :300,000 mth an interval of half an hour. 

 The advantages claimed are less rapid loss of chlorine on storage 

 and less rapid combination of the chlorine in rse. It is supplied 

 in ta'blets packed in amber glass bottles. The tablets have a 

 chlorinous odor. 



On account of the difficulty of securing and preserving cal- 

 cium hypochlurite in a tropical climate, Treherne and Nelson 

 (112) of the Indian army developed a chlorine gas method in 

 1912. The chemicals used are potassium chlorate and hydro- 

 chloric acid. Tne acid is in the concentrated form and the chlo- 

 rate is in the form of five grain tablets. Tw.) unbreakaible bot- 

 tles are supplied. The larger has a capacity of 24 ounces; the 

 smaller of one ounce. Twenty ounces of water are put in the 

 large bottle and three tablets of potassium chlorate are put into 

 the small bottle with two drachms of the hydrochloric acid. The 

 chlorine produced is bubbled through the water in the large bot- 

 tle. When the reaction is finished, the contents of the small bot- 

 tle are added to those of the large one. One ounce of the chlo- 

 rine water added to 5 gallons of the water to be treated gives' 

 a dilution of 1 :440,000. In half an hour the water is declared 

 safe. With this apparatus weighing twelve pounds 9600 gallons 

 of water can be sterilized without refilling. Rishworth, who has 

 had experience with this method in the field, has suggested an 

 apparatus similar to a siphon bottle for making the stock solu- 

 tion. Chlorine stored in small steel bulbs under pressure could 

 be dissolved in the water. 



The Lyster hag employed in the United States Army could be 

 used for any of these methods of purification. It was devised 

 by Major Wm. L. Lyster of the Medical Department. It is a 

 bag of specially woven canvas 20 inches in diameter by 28 inches 



