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W first, the bacteria should decompose the uric acid into urea and 
Itartronic acid; secondly, the urea should be hydrolised to ammonium 
Ijcarbonate by the urea bacteria. According to my own experiments I 
' cannot accept the first part of this supposition, as the formation of 
Martronic acid is but an hypothesis, Gerard not having been able to 
find this substance. But the presence of urea amongst the. products 
he could point out. 
| The first who studied the action of pure cultures on uric acid 
was C. Ulpiani *). He obtained a micrococcus which attacked uric 
acid easily, and found that the maximum and minimum temperatures 
for this organism were respectively 40 9 and 29°, and he presumed 
that its optimum temperature should be 39°. This latter statement is 
|evidently wrong and his supposition, too, that the isolated bacterium 
cannot assimilate glucose, clearly reposes on an erroneous experiment. 
k At his request Cjngolam ascertained that the equation of the 
process is: 
C s H 4 0 # -f 2 H a O + 3 0 = 2 NH a CO NH a + 3CO a . 
I The decomposition of uric acid by microbes has been studied by 
me after four methods. In the first place as an aerobic process; 
I Secondly as an anaerobic fermentation; thirdly as a denitrification; 
and finally as a sulphate reduction. As to the last I can be short: 
under none of the conditions chosen I could obtain with uric acid 
a sulphate reduction by bacteria. 
I As to the other cases, seven species of bacteria called for particular 
"attention; the six first are aerobic bacteria, the seventh is a real 
anaerobic. 
I They are: J. Bacillus fluorescens liquefaciens; 2. Bacillus fluor- 
escens non liquefaciens ; 3. Bacterium calco-aceticum (which is probably 
a new species but has already been obtained in different other ways 
in this Laboratory, where it is kept in culture by that name); 
jp4. Bacillus pyoeyaneus; 5. an aroma-producing species, which I wish 
to call Bacterium odoratum ; 6. a urea-splitting bacterium Urobacillus 
Musculi and 7. a bacillus which causes an anaerobic fermentation 
in uric acid, Bacillus acidi urici. 
The three last mentioned bacteria were formerly unknown, or at 
least not yet produced in pure culture. 
2. The chemical transformation of uric acid 
by the bacteria of the aerobic dor a. 
It was observed that in all the examined species under aerobic 
action the uric acid is oxidised by the bacteria. _ As it was probable 
s ) Rendiconti d. Acad, dei Lincei 1903, T. 12, p. 236. 
