172 
THE ENERGY OF THE LIVING PROTOPLASM. 
energy; but at least with a certain sulpho-acid, the combination 
of formic aldehyde with acid sodium sulphite, I succeeded in 
effecting reduction ; for this in presence of sodium carbonate 
yielded by moderately heating with platinum-black, small 
quantities of sodium sulphide, (I) while the odour of methyl 
mercaptan became perceptible. 
The katalytic action of platinum-black is manifested still 
in another case of physiological interest. If moistened with 
pure caustic lye and exposed to pure air it forms from nitrogen 
and water nitrous acid and ammonia to a small extent. (2) Such 
a process may take place when nitrogen is assimilated by legumi¬ 
nous plants whose roots have entered into symbiosis with 
certain bacteria. The reverse process can also be katalytically 
accomplished ; (3) for a neutral solution of ammonium nitrite, 
which is only decomposed by application of heat, will in presence 
of platinum-black show a continuous development of nitrogen at 
the ordinary temperature. A mixture of 6 g. ammonium sulphate 
with its equivalent quantity of potassium nitrite dissolved in 
130 cc. water developed after addition of 20 g. platinum-black in 
24 hours 191 cc. nitrogen, and in 5 days as much as 768 cc., at 
15 0 and 723 mm. barometric pressure. A similar process takes 
place in cases of putrefaction when nitrates are present, where 
the protoplasm of the bacteria present acts upon the nitrite 
of ammonia formed and liberates nitrogen. 
In all the cases described here the platinum-black remains 
exactly what it was ; it does not act by virtue of any chemical 
affinities, but only by a specific mode of motion. Analogous to 
this is the action of living protoplasm ; it remains what it is 
while it produces various chemical changes in compounds that 
come into contact with it. If it acted by means of chemical 
affinities, it would undergo a change, and that would mean the 
death of a cell when that change amounted to more than slight 
traces in the unit of time. There can be no doubt that the 
active principle is an intense and ceaseless motion of atoms intimately 
(1) We might express this result by the following equation : 
2 CH 2 0 II.S 0 3 Na + 4Na2C03=:Na 2 S + S03Na 2 +HC00Na+5NaHC0 3 
Compare O. Loczv, Ber. Deutsch. Chem. Ges. 33, 3125. 
(2) O. Loezv, ibid. 33, 1443. 
(3) O. Locw, ibid. 301g. 
