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SCIENCE PROGRESS. 



of flow of the river, or, in other words, on the rainfall, and 

 but slightly, if at all, upon either the presence or absence of 

 sunshine or a high or low temperature ; and they are con- 

 firmed by the continuation of these observations during the 

 year 1895 exhibits in diagram No. 10. 



With regard to the effect of sunshine upon bacterial 

 life, the interesting observations of Dr. Marshall Ward 

 leave no doubt that sunlight is a powerful germicide ; still 

 it is obvious that its potency in this respect must be greatly 

 diminished, if not entirely annulled, when the solar rays 

 have passed through a stratum of water of even com- 



MICROBES and FLOW of THAMES 



No. 10. 



paratively small thickness before they reach the living 

 organisms. By a series of ingeniously contrived experi- 

 ments, Mr. Burgess has demonstrated the correctness of 

 this view. 



A sterile bottle about half filled with Thames water was 

 violently agitated for five minutes to insure equal distribu- 

 tion of the organisms. Immediately afterwards a number 

 of sterile glass tubes were partially filled with this water 

 and sealed hermetically. Three of these tubes were 

 immediately packed in ice, and the remainder were attached 

 in duplicate at definite distances apart to a light wire frame 

 which was then suspended vertically in the river. The 



