478 Profs. Percy Frankland and Marshall Ward. 



Thus in this steam-sterilised Loch Katrine water the typhoid bacilli 

 underwent rapid degeneration, the rate of their decline being more rapid 

 at the summer than at the winter temperature ; for at the higher 

 temperature they ivere no longer demonstrable seventeen days after in- 

 fection, whilst at the lower temperature they were still just discoverable 

 even after twenty-one days. 



Essentially similar was the behaviour of the typhoid bacilli in the 

 Loch Katrine water which had been sterilised by filtration through 

 porous porcelain, thus : 



