262 REPORTS ON THE STATE OF SCIENCE.—1913; 
of Chicago. They freeze at a temperature of 0°44°-0:02° C., in a 
manner very similar to that of solutions isotonic with their body-fluids. 
They will survive a temperature of —1° C. They will not survive a 
temperature of —1°8° C. 
The heart-tissue, whether exsected or in vivo, of these frogs survives 
a temperature of -— 2°5°, but is killed by a temperature of —3°0° C. 
Other observers have shown that frog’s muscular tissue will survive a 
temperature of —2°9° C., while the peripheral nerves are not killed by 
much lower temperatures. Hence it appears probable that the cause 
of death is connected with a specific temperature effect on the brain 
or cord. 
Full details of these results will appear shortly elsewhere. It seems 
desirable to continue these experiments with the same species obtained 
at different seasons, and with some tropical species. 
The Committee therefore request to be reappointed, with a grant 
of 101. 
Calorimetric Observations on Man.—Report of the Committee, 
consisiing of Professor J. S. Macponaup (Chairman), Dr. 
F. A. DUFFIELD (Secretary), and Dr. Keira Lucas, appointed 
to make Calorimetric Observations on Man in Heaith and in 
Febrile Conditions. 
ContinuinG the work reported on last year a large number of experi- 
ments have been performed, in which the total heat-production has 
been measured and contrasted with the mechanical work done. A 
statement dealing with the results of these experiments has been 
accepted for publication in the Proceedings of the Royal Society. In 
each of these experiments a subject enclosed in the calorimeter cycled 
against the known resistance of a definite brake at a uniform revolution- 
rate for a period of two hours. Again, as in last year’s experiments, 
there was a noticeable difference between the measured heat-production 
of the first and second hour respectively in each experiment. To test 
the meaning of this apparent difference between the events of the first 
and second hour arrangements were made early in this year’s work to 
add to the measurements formerly made some means of determining 
the carbon-dioxide production, and it is upon the progress made in this 
direction that I have now to make some report. 
It will be remembered that in the original Atwater and Benedict 
calorimeter, from which the details of construction of the body of this 
instrument in Sheffield have been largely copied, apparatus of a very 
perfect kind is arranged to deal with the gaseous exchange of the subject. 
In that instrument the air-steam from the calorimeter is pumped 
through a system of absorption vessels, and thus freed from carbon- 
dioxide, and water is pumped back into the calorimeter with the addition 
of just so much oxygen as suffices to maintain the normal barometric 
pressure of the enclosed atmosphere. From the altered weight of the 
absorption vessels and of the oxygen-cylinder exact data are obtained 
as to the output of carbon-dioxide and aqueous vapour and the intake of 
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