﻿IO MoRRlS-AlREY, On the Rigidity of Gelatine. 



was experienced at first through temperature changes of 

 the laboratory which produced irregularities in the curves. 

 Finally, an underground room whose temperature was very 

 constant, frequently varying not more than J° centigrade in 

 several days was placed at my disposal through the kind- 

 ness of Dr. Hoyle, and no further difficulty was experienced 

 in obtaining consistent results. 



The effect of two sudden rises in temperature on 

 successive days is shown by the shape of the curve in 

 Fig. 6. 



The development of the last part of the curve is 

 exactly similar to that of curves which had not been inter- 

 rupted so that the previous thermal history of the material 

 appears to be without effect. 



I wish to thank Dr. Albert Griffiths, of the Birkbeck 

 College, London, for his valuable suggestions and assist- 

 ance during the above experiments. 



