LABILITY AND ENERGY IN RELATION TO PROTOPLASM. 4OI 
compounds in which both modes of energy exist at the same 
time. 
Compounds in which much potential chemical energy is ac¬ 
cumulated, capable of being suddenly liberated, are the explosives. 
Such cases of instability have no particular interest in connection 
with our special case. The instability I have in view, is the state 
of lability caused by atoms kept in a fierce state of vibration, 
which tend, therefore, to enter into numerous reactions. That such 
labile compounds possess energy of the kinetic kind, becomes 
manifest from the fact that certain such compounds can, by 
imparting their atomic motion to other distinct compounds, cause 
certain chemical changes, without changing themselves in any 
equivalent measure (katalysis). I have mentioned as examples 
in a former Bulletin (No. 4) the katalytic action of maleic acid 
upon ketazines, of ethaldehyde upon free cyanogen, of ethyl nitrite 
upon thio-urea, and the actions of the enzymes. a) 
When a labile substance passes into a stable isomeric one, 
its kinetic chemical energy either diminishes or wholly disappears, 
and assumes, in equivalent ratio, the form of molecular motion, 
i.e., heat. In this transformation the molecular volume decreases, 
while the melting and boiling points are raised. This is an in¬ 
teresting fact, and in full accordance with Stohnianns observa¬ 
tions ; for the labile compounds have a greater thermic value than 
the isomeric stable ones. 1 (2) 3 
Atomic motion of the hydrogen atoms in benzene has been 
supposed by Keknlé to account for the existence of only one 
modification of ortho-compounds, and by Laar {Z) for the hydrogen 
atoms in tautomeric (absolute pseudomeric) compounds, to ex- 
(1) We must always keep in mind that heat, i.e., molecular motion can tinder 
certain conditions easily pass into atomic motion, and that the atmosphere is an immense 
storehouse of heat energy ; thus the continuity of katalytic action is easily explained in 
such cases where an exhaustion of energy would seemingly have to be expected. 
(2) Journ f. prakt. Chem. 46 , 530. There seem to exist exceptions in which the 
larger molecular volume is not coinciding with the larger thermic value, as eg., a 
comparison of aldehydes with the isomeric alkylene oxides would indicate (Ber. Chem. 
Ges. 24 , 652). But we must keep in mind that we have in this case two compounds 
of considerable difference in character before us, which stand to each other by no means 
in such a relation as we have under consideration. 
(3) 'l'he hypothesis of Laar has recently been declared improbable by Traube (Ber. 
Cherii. Ges. 29 , 1723), while Kekule's view has,—at least to a certain extent—, been 
replaced by that of Baeyer. 
