- VOLUME LIII NUMBER 2 
Lite 
POTANICAY GAZETIE 
FEBRUARY 1912 
THE LIBERATION OF HEAT IN RESPIRATION 
GEORGE J. PEIRCE 
(WITH EIGHT FIGURES) 
In September 1908, the Botanicat GazeTTe' published an 
account of some preliminary experiments, of a qualitative sort, in 
which I had used silvered Dewar flasks as respiration calorimeters. 
Continued experimenting with these flasks, and the reports of cor- 
respondents, have further confirmed their usefulness in physiologi- 
cal laboratories. They have also led me to doubt whether, after 
all, a study of the heat yield alone will lead one very far toward a 
solution of the problems presented by respiration.? In this paper, 
however, I propose to give the data of some of my experiments, 
continuing and extending the work previously reported, and after 
that to discuss the possible significance of the results. 
The quantity of heat liberated by germinating peas 
In the preliminary paper already referred to, my experiments 
were necessarily rough, in accuracy below the efficiency of the 
apparatus, which, however, was used under laboratory conditions 
and not under constant temperature. The necessity of working in 
a constant temperature is apparent, when any attempts to deter- 
mine heat yields is being made, since the experiments continue 
through several days. Constant temperature rooms are generally 
hard to secure and hard to keep clear of fungus spores, bacteria, etc. 
* Bor. Gaz. 46: 205-220. 1908. 
? Plant World 12: 193-198. 1909. 
