LABILITY AND ENERGY IN RELATION TO PROTOPLASM. 403 
atom of the aldehyde group sets the hydrogen atoms of the ami- 
do-group into rapid motion, as,—to give a rough analogy—a 
moving magnet held beneath a sheet of paper moves iron 
particles spread upon the sheet, which cannot unite with the 
magnet, the sheet holding them back. These moving hydrogen 
atoms of the amido-group, again, will exert an influence upon the 
labile hydrogen atom in the aldehyde group which, in con¬ 
sequence of the repulsion it suffers, is compelled to increase 
the amplitude of its oscillations. n) Thus we can understand why 
the lability of an amido-aldehyde is very great and the inclination 
to spontaneous changes much more marked than with common 
aldehydes. The degree of lability, however, is much influenced 
by the more or less saturated condition of the compound, the re¬ 
lative position of the labile atoms, and the relative number of the 
CH 2 -groups. Thus, amido-ethylaldehyde is much more labile 
than the d-amido-valeraldehyde ; the latter remaining even un¬ 
changed on distillation under diminished pressure, while the 
former changes soon after it is liberated from its combination 
with acids. The amido-benzaldehydes, again, are less labile, 
although reacting with great readiness and readily changing 
when brought in contact with dilute hydrochloric acid. 
Such a state of kinetic chemical energy was foreseen by 
me to exist in the active albumin, which I consider a pro¬ 
duct of the condensation of the di-aldehyde of aspartic acid (cf. 
Bulletin II. No. 2). The active group a which, by atomic mig¬ 
ration, easily passes into the passive group ß , would, according 
to my deduction, have the following structure : 
-CH-NH 2 
I 
— C — CHO 
a 
Aldo-amido-structure. 
-CH-NH 
i / 
=C—CHOH 
H y c 1 r ox y 1 -i m i d o-s t r u c t u re. 
The one essential to my theory is the constitution of the labile 
(active) group and the conclusion that the active albumin is a 
product of the condensation of aspartic aldehyde, which may be 
built up in the living plant cells of formaldehyde and ammonia; a 
(i) Hydrogen atoms of a high degree of lability behave sometimes somewhat like 
nascent hydrogen, leading to powerful reductions. 
