( 63 ) 
|^vident when comparing the image of a culture in its first phase of 
^fermentation to that of one where the fermentation has ceased. In 
-the former case the irregular uric acid crystals and the boat-shaped 
ones of the magnesium phosphate are only to be seen; in the latter 
the characteristic “coffins” of ammonium-magnesium phosphate. 
In the deposit at the bottom we observe numerous highly motile 
rods,, whose motility rapidly decreases at access of air; so, there is 
reason to believe that the excess of magnesium phosphate acts also 
Ibeneficially on the bacteria, by enabling them easily to reach the 
places with the most favourable oxygen tension. 
If the fermenting fluid is poured on the plate with admission of 
air, no microbes occur which ferment the uric acid; but B. calco- 
aceticum does develop. 
| The fermentation organism proper which was hitherto unknown, 
and shall be called Bacillus acidi urici, is a spore-forming, strongly 
motile, obligative anaerobic microbe, whose photographic image is 
given here. 
The middle length of the rods is 5fi; their width is 0.7 p, and 
the diameter of the spores is about 2.5 p. The rods are excessively 
motile but by cultivation on plates the motility gets quite lost. The 
spores are round and placed at the ends, but eventually they are 
oval. The colonies on broth-agar are transparent, round or of more 
irregular shape, and very variable in size. 
I As to the products of fermentation the following was established. 
The escaping gas consists solely of carbonic acid. Quantitative tests 
f proved that per one molecule of uric acid three molecules of carbonic 
acid are liberated. It was further observed that the urea groups are 
converted into ammonium carbonate, and that acetic acid is formed. 
The quantity of this acid greatly depends on the nature of the 
fermentation; a crude accumulation produces more acetic acid than 
a fermentation that has been repeatedly transferred, or has been 
obtained by pure culture. 
As to the chemism of the fermentation the production of carbonic 
acid corresponds with the formula as given by Strecker a ) for the 
hydrolytic decomposition of uric acid: 
C s H 4 N 4 0, + 5 H 2 0 == C a H,NO, + 3 C0 2 + 3 NH, 
Glycocoll 
But glycocoll I have not been able to point out. It is however 
very well possible that this substance is reduced to ammonium acetate 
by the further action of the bacteria. 
Liebig’s Amialen; Bd. 146, pag. 142,1868. Zeitschr. f. Ghemie 1868 pag. 215. • 
