INSTITUTE, PUSA, FOR 1918-19 113 



VI. Sterilization of water. 



Attention was drawn to this subject owing to the out- 

 break of a severe cholera epidemic in the neighbourhood 

 of Pusa, and the difficulty of obtaining antiseptics. 

 Attempts were made to obtain a stable hypochlorite solu- 

 tion by electrolytic methods and the work was transferred 

 to Shillong whilst I was on hill recess there; owing to the 

 kindness of the Director of the Pasteur Institute who 

 allowed me to work in his laboratoy and the courtesy of 

 the officers of the Local Government who allowed me to 

 make use of the electric current supply of Government 

 House, I was able to continue this investigation and was 

 also fortunate enough to secure the assistance of Captain W. 

 Hodgkinson, R.E., who was put on deputation by the Army 

 Department for this purpose and has since been working 

 on this problem at Pusa. It has been found possible to 

 produce a solution containing from 3-4 per cent, available 

 chlorine by electrolysis from purely Indian raw materials, 

 thus avoiding the use of imported bleaching powder and 

 having the consequent advantage of avoiding the great 

 loss of chlorine in transit and in store incidental to the 

 use of " bleach ; " at the same time this solution (now known 

 as E. C.) can be prepared anywhere where electric current 

 is available, and can be made of standard strength merely 

 by reading figures on an ordinary current meter without 

 expert knowledge either of chemical or electrical methods. 

 This work was done at the instance of the Stores Depart- 

 ment of the Indian Medical Service with the object of pro- 

 viding a reliable method of sterilizing water for troops on 

 field service or elsewhere; the principal difficulty encoun- 

 tered has been to obtain a sufficient degree of stability to 

 allow of storage for such periods of time as may be neces- 

 sary for transport to situations where electric current is 

 unavailable ; the degree of stability possessed by E. C, like 

 that of all hypochlorite solutions, varies inversely with the 

 temperature of storage, but owing to the method of pre- 

 paration and the use of an appropriate stabilizer it should 

 be sufficient to ensure its efficiency under most conditions 



