50 THE FORMATION OF PROTEIDS IN PLANT-CELLS. 
We have mentioned above that a certain kind of bacillus 1 ) 
can utilise formic acid (as sodium salt) as a source of caibon 
which is of special interest. Here the first step is most probably 
a transformation into glyoxylic acid and a subsequent splitting 
of the latter into form-aldehyde and carbon dioxide,“) as may be 
expresed by the following equations; 
2 H.COOH = 0 :CH.C 00 H + H 2 0 
0 :CH.C 00 H = CH 2 0 + C 0 2 
The necessary energy is evidently furnished here by the 
oxidation of a certain portion of the sodium formiate into 
sodium carbonate, clearly indicated by the gradual increase of 
the alkaline reaction. The more energy, however, a compound 
yields in being utilised for protein-formation, the better the 
effect must be; we can therefore understand, why methyl alcohol 
is a better source of carbon than form-aldehyde (in the shape of 
CH. 0 H.S 0 3 Na) or formic acid. Methyl alcohol yields by its 
transformation into form-aldehyde an amount of energy, that form¬ 
aldehyde cannot furnish ; the necessary energy must be gained 
here by oxidation of such molecules to carbon dioxide and water. 
We understand now why oxalic acid, paiabanic acid, uiea 
or guanidin cannot be used as sources of carbon ; this is because 
these compounds cannot be transformed by bacteiia into form¬ 
aldehyde. If pyridin, pinacon or dimethyl-oxypyrimidin will 
not serve, it is very probably on account of the considerable 
resistance they offer to oxidising influences. If amidoacetal, 
glyoxal, or ethylendiamin are incapable of yielding a bacte¬ 
rial vegetation, and diacetonamin and acetoxim apparently 
do so only with great difficulties, we might suspect a ceitain 
degree of poisonous character, that cannot make its appealance 
in presence of a nutrient like peptone. 3 ) But foi the diffeience 
of physiological value between the stereo-isomeric maleïc and 
fumaric acid, we have at present no explanation. 
As a general rule we find that compounds, containing the 
1) This bacillus, which I named Bacillus methylicus , can also utilise the 
combination of form-aldehyde with primary sodium sulfite, CH 2 0 H.S 0 3 Na oxyme- 
thylsulfonate of sodium in 0,5% solution. 
2) Compare Koenigs , Ber. Deutsch. Chem. Ges. 25, 801. 
3) Some of the combinations of this group might perhaps be utilised in much 
higher dilutions than tested (0,5°/ 0 ). 
