AMERICAN 
JOURNAL OF BOTANY 
Vol. I May, 1914 No. 5 
THE INFLUENCE OF TEMPERATURE ON CHEMICAL 
REACTION IN GENERAL* 
Frederick Barry 
Any inquiry into the effect of a change of temperature upon a 
physical or chemical process involves at the outset considerations of 
a fundamental character as to the nature of physical change in general. 
In order that the point of view from which it is habitual for the physi- 
cist or the chemist to examine such a question may be clearly definejJ, 
so that the short discussion which follows may not be too much ob- 
scured by its necessary brevity, I shall venture at once to summarize 
that group of general conceptions in terms of which physical processes 
are most understandingly described and correlated. Familiar though 
these ideas may be to us all, we shall thus recall more vividly than we 
otherwise might that habit of thought which alone has been fouxid 
serviceable to the practical understanding of natural phenomena, 
and the character of its premises. 
As a result of the long-continued series of investigations which we 
associate with the immortal names of Rumford, Mayer, Helmholtz, 
and Joule, we have come to look upon all the natural occurrences 
that fall within the range of our experience as instances of a continuous 
change in the distribution of that which we call energy; of which 
mechanical work, heat, electrification are diverse but interconvertible 
manifestations. It would be gratuitous in this place to trace the steps 
by which men slowly came to a full realization of the significance of 
this remarkable concept, by which phenomena so dissimilar could be 
grouped together as of one essential quality. Nor is it necessary to 
dwell upon the tremendous value of such an idea — derived wholly 
* Paper read in the Symposium on " Temperature Effects " before the Botanical 
Society of America at Atlanta, Dec. 31, 19 13. 
[The Journal for April (i: 145-202) was issued 23 May 1914.] 
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