213 



time: in minutes 

 _^ ^. 



2 10 



Fig. 31. 



"1 



I 2 10 20 30 



Time-temperature curves of devitrification of a 20% gelatin 

 solution. The dots indicate a complete devitrification; the circles signify that 

 devitrification was not completed at the time and temperatures recorded. 



which differ by only 0.4 degree (- 31.4^ and - 31.8° respec- 

 tively; devitrification in 5 minutes). For determining 

 these temperatures, two drops, one of each solution, were 

 mounted on the same preparation and the increase in 

 opacity of the two was observed simultaneously. 



This lowering of the devitrification temperatures with 

 increase in concentration reminds one of the freezing point 

 lowering of aqueous solutions. Nevertheless, we cannot 

 say at the present time to what extent these two processes 

 are referable to the same cause. 



