646 LABORATORY HINTS 



communis is a very rare organism in its waters, while other organisms 

 are particularly common. 



Clemesha comes to these conclusions : : — 



(i) That standards in use in cold climates are useless, and worse 

 than useless, in tropical climates. 



(2) That il is necessary lu separate the individual species of bacilli 



by well-established tests and to study their characteristics and 

 their position in nature. 



(3) That it is advisable to classify all lactose fermenting organisms 



according to their ability to resist the action of sunlight, and 

 on this to base the standard of bacterial purity. 

 The general conclusions of his experiments are : — 



The Bacteriology of Earth. 



(i) B. cloacae, B. grunthal, B. Xcn 75, and to a less extent B. 

 coscoroba, are capable under favourable conditions of remain- 

 ing alive in the soil for a considerable length of time, probably 

 up to three to four years. 



(2) Faical organisms of an}- kind do not appear to exist in large 



numbers after they have been in the earth for longer than 

 one to two years; night soil buried in the ground, even in 

 large quantities, loses most of its organisms in this period. 



(3) Sporogenes enteritidis spores are capable of remaining alive in 



the ground for a period of something between three to four 

 years. 



(4) B. coli communis has never been isolated from the trenching 



ground samples, hence it is j^robable, though not certain, 

 that this organism does not remain alive in the ground as 

 long as the more resistant organisms like cloacae, &c. It has 

 been proved in one experiment to exist in the ground for a 

 period of ninel}'-seven days. 



The Bacteriology of ]]'ater and Fccccs during Monsoon Weather. 



(i) The conditions obtaining during a heavy monsoon when fresli 

 faeces mav find their way easily into water, the whole country 

 being submerged, is in some ^\ay connected wiih the appear- 

 ance of a set of rare micro-organisms in all the water supplies 

 over a wide area. This fact has not been noticed with 

 previcHis and subsequent heavy rain. 



(2) These and allied bacteria may suddenly become extremely 

 common in the faices of animrds and man. The cause of this 

 increased prevalence is unknown. 



