( 517 ) 
erythrogenes and Urobacillus jakschii in series of culture-liquids, which, 
besides ureum, contain a diminishing quantity of asparagina or 
ammoniummalate. 
Indeed a very trifling quantity of these materials proves to be 
sufficient for a normal ureum-decomposition. 
From the results of the investigations, laid down in the subjoined 
table, it follows that the Bacillus erythrogenes at a normal growth 
splits 500 mG. of ureum with 20 mG. of carboncompound whilst 
the Urobacillus jakschu splits 1800 mG. of ureum with 10 mG. 
of carbon-compound. 
With smaller quantities of carbon-compound the growth of both 
microbes is considerably less than above. 
The quantity of energy, which in the erythrogenes- and jakschi- 
cultures was developed by the splitting of the ureum, amounts respec- 
tively to + 96°/, and 99°, of the total sum of energy developed in 
these cultures. 
At the same time it appears from these numbers that the less 
splitting species want a larger quantity of carbon-compound for the 
decomposition of a certain quantity of ureum than the very strong 
splitters. 
The figures in the subjoined table denote the number of c.c. N H,SO,, 
necessary for neutralizing 50 e.c. culture-liquid after five days of 
culture at a temperature of 30°. | 
The 50 ce. eulture-liquid inoeculated with the Bacillus erythro- 
genes, consist of water, in which 0.05 ®/, K,HPO, 2°/, ureum and 
the carbon-source are dissolved. 
The 50 ce. culture-liquid infected with Urobacillus jakschi has, 
besides 5°/, ureum instead of 2°/, ureum, the same composition as 
the above mentioned. 
Decomposition by Bacillus erythrogenes. 
Quantity of carbon-source in milligrammes 50 40 30 20 10 
5 
Decomposition if the latter is asparagine 18.5 175 17 a 13 8 
Decomposilion if the la'ter is amm. malate 19.8 17.9 18.5 180 142 9.5 
Decomposition by Urobacillus jakschu. 
Decomposition if the latter is asparagine 61.5 60 59 60 54 42 
Decomposition if the latter is amm. malate 60 58 60 59 56.5 39 
§ 2. Caleiumsalts of organic acids as a carbonsource for 
ureum-splitting microbes. 
The organie acids proceeding from plants or produced by fermen- 
tation thereof are principally neutralized in arable soil by the frequently 
occurring calciumearbonate. 
