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.' 0 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 (J-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 

 mc 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 ft, would, according 

 to my deduction, have the following structure : 



The one essentia! 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 



-CH-NH 



-CH-NH 



I / 

 =C-CHOH 



=C-CHO 



Aldo-amido-st met ure. 



a' 



(1) Hydrogen atoms of a high degree of lability behave sometimes somewhat like 

 nascent hydrogen, leading to powerful reductions. 



