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. (1) 



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 Stohmanris observa- 

 tions ; for the labile compounds have a greater thermic value than 

 the isomeric stable ones. (2) 



Atomic motion of the hydrogen atoms in benzene has been 

 supposed by Kekule to account for the existence of only one 

 modification of ortho-compounds, and by Laar (3) 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 wider 

 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 he 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) Ihe hypothesis of Laar has recently been declared improbable by Traube (Ber. 

 Chem. Ges. 29, 1723), while Kekule s view has, — at least to a certain extent — , been 

 replaced by that of Iiaeyer. 



