5o THOMPSON YATES AND JOHNSTON LABORATORIES REPORT 
It may first be pointed out that the supposed thermodynamic proof that the 
point of equilibrium of a reaction cannot be disturbed by a body which is not itself 
altered in the reaction is erroneous, since the proof given excludes without adequate 
grounds the view that the catalyser, when present, may alter, without itself being 
permanently changed, the distribution of energy between the other constituents by 
altering the equilibrium of potentials of the thermal volume (osmotic) and chemical 
potentials of the system. 
The thermodynamic proof above-mentioned consists in instituting a cycle in 
which, supposing that the point of equilibrium is not the same in the presence and in 
the absence of the catalyser, the substance with the higher amount of chemical 
energy is formed in the presence of the enzyme ; the enzyme is then supposed to be 
removed, and the excess of substance with higher chemical energy ; and then the 
enzyme may be once again employed for forming a fresh quantity of substance of 
higher chemical energy from the substance of lower chemical energy. In this manner, 
chemical energy may be perpetually formed without expenditure of energy, since the 
enzyme is not changed in the process. 
The fallacy of the reasoning lies in the fact that the energy employed in the 
formation of chemical energy comes from other forms of energy present in the 
solution, such, e.g., as volume or osmotic energy, by a redistribution of potentials due 
to the presence of the catalyser in the solution, and that immediately on removal of 
the catalyser in the second stage of the imaginary cycle, the system will revert to its 
old position by an inverse distribution of potentials, so that the substance formed in 
the presence of the catalyser is reconverted back in the absence of the catalyser into 
the substance from which it was formed, accompanied by an inverse flow of energy. 
There is hence no theoretical basis for the view that the equilibrium point must be 
the same in a chemical system in the presence and in the absence of a catalyser. 
That an enzyme cannot start a reaction which will not proceed in its absence is merely 
a particular case of the above, and hence similar reasoning may be applied to it. 
Under ordinary conditions, the synthesis of a substance of higher chemical 
energy from one of lower chemical energy can only occur, either when the difference 
in energy is small and can be taken from the volume energy (osmotic energy) of 
the solution, e.g., as in the synthesis of maltose from dextrose in concentrated solution ; 
or when the catalyser is supplied with some form of energy extraneous to the system ; 
as in the synthesis of organic plant substance by chlorophyll-containing cells from 
solar energy, or by fat-forming cells by the use of a degradation of the chemical energy 
of a part of the system. For a higher form of energy such as chemical energy cannot 
be formed from heat energy at the same temperature. Hence usually, the work of 
a catalyser consists in starting, or in accelerating, a reaction which runs exo-thermically 
with degradation of chemical energy and evolution of heat. 
Experimental results also support the view that catalysers are capable of starting 
