l60 TIME 



in chemical reactions. These experiments led him to a value 

 of this coefficient comprised between 275 and 2-85. This is 

 a satisfactory accord — if one takes into account the difficulties 

 of the experiment and the small difference in temperature — 

 with the mean value of 2-5 for an increase of 10° C. (It may 

 be remembered that I mentioned (page 98) experiments 

 made at the Rockefeller Institute on cold-blooded animals 

 (crocodiles) which clearly demonstrate the influence of the 

 Van't Hoff coefficient in the cicatrization of wounds.) 

 M. Fran9ois' interesting results were entirely confirmed and 

 extended by Hoagland in 1933.^ Finally Wahl, Graben- 

 berger, and Kolmus published very curious facts which also 

 confirm our thesis and establish the chemical nature of the 

 mechanisms which result in our psychological appreciation of 

 time. When studying bees, ants, and termites, trained to 

 come at a certain hour and take their food, the authors ascer- 

 tained, by modifying the temperature, that an increase in 

 temperature forced these insects to shorten the interval of 

 time between two meals. This is the equivalent of an apparent 

 dilatation of the time perceived by them. A decrease in 

 temperature brought about a contrary effect. There can 

 therefore be no doubt as to the nature of these phenomena. - 

 The comparison of these two series of experiments demon- 

 strates clearly the relation between the rate of cicatrization of 

 wounds and the psychological appreciation of time. They 

 both rest in last analysis on a chemical basis. There is no 

 break of continuity in the chain of our reasoning, every link 

 of which derives its solidity from an experimental confirmation. 

 Consequently, when we refer to sideral time as being the 

 canvas on which the pattern of our existence is spread, we 

 notice that the time needed to effectuate a certain unit of 

 physiological work of repair is about four times greater at 

 fifty than at ten years of age. Everything y therefore, occurs as if 



^ H. Hoagland, Pace-makers in Relation to Aspects of Behaviour. 

 MacMillan, New York, 1935. 



^ This information was given to me by Prof. Pieron, to whom I 

 express my thanks. 



