14 BACTERIA IN DAILY LIFE 



however, besides demanding space and time, in- 

 sist upon their workshops being well ventilated, 

 and if the supply of fresh air is in any way cur- 

 tailed they stop work entirely. Hence the ventila- 

 tion of the aerobic workshops becomes a matter 

 of primary importance if the valuable services of 

 these labourers are to be retained. To ensure 

 a sufficient supply of air being provided, it has 

 been found advisable to have two or more aerobic 

 workshops or bacteria contact beds, and the sewage 

 is passed from one on to a second, and so on, until 

 the purification is complete. Under proper man- 

 agement the 'sewage should leave the works as an 

 inodorous, almost pellucid liquid, incapable of 

 putrefaction, which may be turned into rivers or 

 other waterways without fear of rousing the wrath 

 of local riparian authorities. 



But whilst the commercial side of bacteriology, 

 so to speak, has made such great strides, the purely 

 scientific applications which have been made of 

 the facts it has furnished have by no means lagged 

 behind. Chemists, from Pasteur downwards, have 

 made use repeatedly of special bacteria to per- 

 form delicate operations in the laboratory which 

 other methods have either failed to accomplish or 

 have performed in a clumsy and less expeditious 

 manner. 



There can be no doubt that, as our knowledge 



