ISOMERIC CHANGE 



231 



thousand times greater than the lowest value recorded for 

 purified water, it would evidently be a matter of extreme 

 difficulty to arrest the change by diminishing the electrical 

 conductivity of the solution, and no experiments in this direction 

 have yet been attempted. 



Nitrocamphor. — The first observations of arrested isomeric 

 change in the case of nitrocamphor ] were due to the happy 



Fig. 



Fig. 2. 

 Change in rotatory power of nitrocamphor in solution in chloroform. 



accident of using chloroform as a solvent. The character of 

 the observations made is well shown in fig. 1. In the first 

 case a 10 per cent, solution was kept in a polarimeter tube 

 during seven days ; a very gradual decrease in the rotatory power 

 of the solution indicated that isomeric change was perhaps 

 1 Lowry, Trans. Chem. Soc. 1899, 75, 220. 



