BACTERIOLOGY AND WATER 115 



ised by a remarkable paucity of bacteria ; in the 

 chalybeate and alkaline springs sometimes as few 

 as two microbes only in a cubic centimetre were 

 found, and the largest number recorded only 

 amounted to forty-five. The satisfactory signifi- 

 cance of such figures will be appreciated when 

 we realise that they rival very closely the numbers 

 which characterise the purest spring and the 

 deepest well water, and which are usually re- 

 garded as the aristocracy among drinking-waters. 

 Of special interest is Dr. Fazio's discovery that 

 the variety of bacteria present in these waters 

 is extremely restricted, as a rule only three, or 

 at most four, different kinds of bacteria being 

 detected. 



This is also characteristic of the pure water 

 derived from deep wells sunk into the chalk, 

 usually but very few different kinds of bacteria 

 being found amongst the limited number of their 

 Lilliputian inhabitants, whilst in samples collected 

 from rivers or other surface sources, especially 

 those which have been polluted with sewage or 

 similar refuse matters, the bacterial population is 

 frequently as diverse as it is unwieldy. 



From the exacting point of view of the un- 

 compromising bacteriologist the most satisfactory 

 waters in existence for drinking purposes should 

 be those derived from sulphur springs. Dr. Fazio 



