THE EXAMIA'ATION Of WATER 645 



Total colony count in agar at 37° C\ \\as 700 per c.c. 

 Fsecal bacilli present in o'oi c.c. 

 Sporogenes milk lest plus in 20 c.c. 



Experiment (4). 



Sample from well Xo. 7 of the Khartoum water supply. 

 Gas was present in MacConkex's medium when the latter was 

 inoculated with 50 c.c. of the sample. 



Sporogenes milk test negative in 20 c.c. 



Remarks on these and other Tests. 



The observations have been too few to justify any definite con- 

 clusions being arrived at with regard to the position that the B. coli 

 occupies in this country as an indication of recent pollution. 



Experiments should be carried out every month of the vear to 

 determine the effects of external natural forces, such as sunshine and 

 rain on all organisms of faecal origin. 



There was more faecal pollution present in a " falling " than in a 

 "rising" river, although the colony count in the latter was nearly 

 four tinies as great as in the former. 



Experiments have demonstrated that there are different types of 

 lactose fermenters present in human freces in different months of the 

 year. 



Experiments also go to prove that B. coli communis is extremely 

 susceptible to the bactericidal eft'ects of sunlight, and that B. cosco- 

 roba, I?, schaefferi, B. neapolitanus, and B. vesiculosis are extremely 

 resistant. 



B. coli were not found in trenches seven days old, hence soil 

 destroys them. 



The chief bacilli found in the faeces of animals were : — 



B. coli, B. clcaccC, B. neapolitanus and others in goat fceces. 



B. schaeft"eri and B. neapolitanus in cow faeces. 



(C) Probably the best methods and the best data yet given come 

 from Major Clemesha of the Madras Presidency. 



He states that there must be considerable doubt as to whether the 

 standards of purity in common use amongst sanitarians in England 

 were suitable to India. 



Most Indian waters are loaded with fa?cal contamination that no 

 analyst in England would dream of passing as fit for human con- 

 sumption. And yet it is remarkable that the evil effects of using such 

 water as drinking-water are not al\va\s apparent. 



The resulting diseases are not in proportion to the cause at all times. 



In England a cautious Medical Ofificer would condemn water for 

 drinking which contained true coli in i c.c, but in India the B. coli 



