PRODUCTS OF VITAL ACTIVITY. 145 
widely distant sources, are similar in their morphological and bio- 
logical characters, and at least belong to the same group. In a com- 
munication made in 1891 Winogradsky arrives at the conclusion 
that the ferments which cause the oxidation of ammonia and pro- 
duction of nitrites are not capable of producing nitrates, but that 
other microdrganisms are concerned in the oxidation of nitrites. 
In sterilized soil to which a pure culture of his nitromonas was 
added nitrites only were produced, and the presence of various 
microédrganisms common in the soil did not result in the forma- 
tion of nitrates so long as the specific ferment was absent to which 
this second oxidation is ascribed (nitrifying bacillus of Winograd- 
sky). 
Phosphorescence.—Several different bacteria have been studied 
which, in pure cultures, give rise to phosphorescence in the medi- 
um in which they are cultivated. In gelatin cultures the light 
is sufficient in some instances to enable one to tell the time by a 
watch in a perfectly dark room, and such cultures have even been 
photographed by their own light. 
The phosphorescence is influenced by changes in the culture 
medium and by conditions of temperature, but we have no exact 
knowledge of the mode of its production. The Bacillus phosphores- 
cens from sea water in the vicinity of the West Indies gives the 
most striking results, especially when planted upon the surface of 
cooked fish and placed in an incubating oven at 30° C. Two other 
species have been studied by Fischer—one obtained from the water 
of the harbor at Kiel, and the other a widely distributed species 
called by Fischer Bacterium phosphorescens. Katz (1891) has de- 
scribed several species obtained by him from sea water and from 
phosphorescent fish in the markets at Sydney, New South Wales— 
Bacillus smaragdino-phosphorescens, Bacillus argenteo-phosphores- 
cens, Bacillus cyaneo-phosphorescens, Bacillus argenteo-phosphores- 
cens liquefaciens. 
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