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THE ROYAL SOCIETY OF CANADA 



The above experiiucnts show tlat the frog's heart can survive a temperature 

 of — 2-5° but cannot survive a temperature of — 3°C. 



C. Experiments on the manner of cooling of the frog. 



Experiment 13. A medium sized frog, weighing 31-5 grams, was bound, and 

 the bulb of a small thermometer inserted through the gullet into the stomach. An 

 equal weight of Ringer's solution (NaCl, 0-7%; KCl, 003%; CaCl^, 0025%) was 

 placed in a beaker, and a thermometer placed so that the bulb was in the centre of 

 the solution. The frog and beaker were placed side by side in a large glass jar, and 

 exposed to an external temperature which during the experiment sank from — 10° 

 to — 11- 5°C. Temperature readings were taken every few minutes with the follow- 

 ing results: — 



Curves, plotting temperature against time are shown in figure 1 . The deductions 

 from this experiment are dealt mth on p. 111. They were confirmed by 



Experiment 14. Mar. 19th. This was carried out m a manner precisely similar 

 to the previous experiment. 



