THE FORMATION OF PROTEIDS IN PLANT-CELLS. 
49 
I have observed farther that not only methyl alcohol, but 
also methylal and methyl sulfuric acid 1 ) may in proper dilution 
(o,2-0,3%) be used as food by bacteria, i. e. as material for 
building up protein and protoplasm. The group then used for this 
purpose must contain only one atom of carbon and cannot be any thing 
else but form-aldehyde, the same substance that forms by condensation 
various kinds of sugar. Neither acetic, glycolic, nor amidoacetic 
acid can be utilised as such, but they may lead by oxidation 
to one compound which can be utilised, viz. to form-aldehyde) no 
other unsaturated atomic group could result, suitable for 
synthesis. This oxidation 2 ) in the cells may be expressed by 
the following equation in the case of acetic acid : 
CH 3 .COOH + 0 2 = CH 2 0-f C0 2 + H 2 0 
If this conclusion is correct, then we can understand, why 
substances containing the group CHOH are very favorable for 
nutriment and why the useful qualities increase with the number 
of these groups (the polyvalent alcohols, the polyvalent acids). 
We can understand furthermore, why such substances are 
capable of nourishing certain bacteria endowed with fermentative 
properties , even in the absence of air, while compounds without 'this 
group can be used as food only in the presence of air, oxidation 
being then necessary to produce this CHOH-group or the 
isomeric formic aldehyde. But can that conclusion be admitted 
if formic aldehyde is a poison? No doubt this seems an objec¬ 
tion of weight, but if we consider how easily the formic aldehyde 
is changed under condensating influences and how indifferent 
certain compounds of this aldehyde are, the objection no longer 
appears so serious; we must only adopt the view that the formic 
aldehyde undergoes rapid transformations and that no molecule 
formed remains unchanged for a second. 3 ) 
1) In this case an alkaline reaction is necessary for obvious reasons. 
2) Oxidation by respiration has here evidently not only the physical rôle of 
yielding energy, but also a direct chemical function in preparing the suitable group 
for synthesis. 
3) Compare O. Loezv, Ber. d. Deutsch. Chem. Ges. 22, 484. Synthetical 
processes require substances of a certain lability ; very reactive substances however 
are more or less poisonous. The objection of some botanists to the view of the 
formation of sugar from form-aldehyde in plants is not more tenable since Bokorny 
has shown that the combination of form-aldehyde with primary sodium sulfite can 
be utilised by plants for the production of starch. Landw. Jahrb. 1892. 
