130 BACTERIOLOGICAL EXAMINATION OF WATER. 



Potato. Thick yellowish-brown growth. 



Milk. Coagulated in twenty-four hours at 37 C. 



Peptone and Salt Solution. A marked indol reaction obtained. 



Broth. A diffuse growth. A slight surface pellicle is formed. 



Nitrate-broth. Nitrates are largely reduced to nitrites. 



Glucose-gelatine. Marked gas formation. 



Microscopical Characters. Small non-motile bacillus, usually 

 in pairs. Spore formation present. 



It will not grow below 10 C. ; requires from 10 to 12 C. ; 

 at 15 C. acid is produced, which ceases at 45'5 C. 



Bacillus Urese. 



This micro-organism was isolated from ammoniacal urine by 

 Jaksch. It was found by Tils in Freiburg water, and by Lustig 

 in river water. 



Gelatine Plates. The surface colonies form small, transparent, 

 finely granular films, with an irregular margin, somewhat re- 

 sembling the colonies of B. typhosus. 



Gelatine-stab. A surface growth like the colonies ; also a fine 

 white growth along the stab. 



Glucose-gelatine. No gas formation. 



Milk. L T nchanged. 



Potato. A thin white growth. 



Agar. A white expansion, not characteristic. 



Broth. A diffused growth and a deposit forms at the bottom 

 of the tube. 



Peptone and Salt Solution. No indol reaction obtained. 



Microscopical Characters. A small motile bacillus. It converts 

 urea into ammonium carbonate. 



Bacillus Fluorescens Putridus. 



This microbe was isolated from water by Flugge. It is 

 considered by Mace to be characteristic of foul waters. A 

 culture from Krai's laboratory gave the following cultural 

 reactions : 



Gelatine Plates. The colonies both in the depth and on 

 the surface are small ; but, later on the surface they grow 

 out as greyish-white expansions, with a circular or slightly 

 irregular margin. They are thicker at the centre than at the 



