MICRO-ORGANISMS IN WATER 



CHAPTEE I 



STERILISATION AND THE PREPARATION OF 



PLATES I. AND II. 



BACILLUS PRODIGIOSUS it referred to on page 440 

 ,, SUBTILIS ., ., 417 



RAMOSUS ., , 419 



VIOLACEUS 472 



ARBORESCENS . 482 



may in addition be sterilised by (4) filtration. 



(1) Steam or moist-heat sterilisation. This is most 

 conveniently effected by means of the ' steam steriliser/ 

 devised originally by Koch, Gaffky, and Loffler, and 

 which has the exceedingly simple form represented 

 in the figure below. The cylinder is covered with felt 

 or asbestos, to prevent loss of heat, and the bottom is 

 constructed of copper, under which are placed one or 

 more bunsen or other smokeless burners, according to 

 the size. The heat applied must be sufficient to keep 

 the water in such vigorous ebullition that steam issues 



