( 798 ) 
at least the possibility will not be denied that the reaction does not 
take place so, that H, and Cl, are dissociated to atoms H and Cl, and 
these atoms meet again with formation of HCI, but so that a molecule 
H, meets a molecule Cl,, and that with a suitable position of these 
molecules the bond between the H atoms and the Cl atoms inter se 
is only broken in consequence of the mutual attraction of the H and 
the Cl atoms and immediately passes into a new bond. If we 
imagine the course of the reaction in this way, a value of the 
energy may be indicated which undoubtedly with greater justice 
may be expected to determine the velocity of reaction than the heat 
of dissociation in the atoms which is here devoid of any chemical 
significance. In consequence of the approach of the molecules H, 
and Cl, there is, namely, a certain loss of potential energy through 
the action of the attracting forces; when the two molecules have 
approached each other to a certain distance, the potential energy will 
attain a minimum value, a condition which is indicated by what 
is contained between the brackets in the following symbolic represen- 
tation : 
H- 431 lee GI 
CI OQ O—O0 
es i Yael 
If then the molecules of hydrochloric acid again separate, the poten- 
tial energy will rise again in consequence of the work done against 
the attractive forces. 
Now in our opinion it may certainly not be considered as impos- 
sible that this state of minimum potential energy is to be considered 
as the above-mentioned “intermediate state”. In the value of £ of 
equation (10) the corresponding potential energy and entropy, at 
least the corresponding constants, will have to occur. 
We may state once more that we by no means mean to say 
that in the mentioned reaction, or any other reaction, the process 
must be exactly as we sketched it. We only wanted to make clear 
first of all that it necessarily follows from the value for / that 
‘intermediate states” play a part; further that these intermediate 
states may be of various kinds, and can be entirely different in one 
reaction from that in another. So a universally holding splitting up 
of the heat of reaction into two parts, for reactions in which no 
intermediate products occur, as of late was tried by Travrz, will 
probably be impossible. There is still less chance that it is to be 
