198 Miss Homer, The Resolution of Salts, etc. 
of crystals were obtained the solutions stood for some three months 
or more. With regard to the valerate it was found that after three 
recrystallizations from acetone and petroleum ether ’108 grs. 
substance in 12 c.c. water in a two decimeter tube gave a rotation 
— 1’97° ; therefore [M] n = — 391’5°. 
After four crystallizations ’030 grs. substance in 12 c.c. water 
in a two decimeter tube gave a rotation — ’59° ; therefore 
[M] d = - 402°. 
The rotation for the active ammonium ion = — 398°. 
In this case racemisation has not occurred, but it is impossible 
to say whether separation of the two salts had been effected. 
The author tried to obtain the active ammonium salts of the 
acids by treating their silver salts with the active iodide in 
alcoholic solution, on the water bath at 100° C. Here again there 
was racemisation. 
If the active ammonium hydroxide could be obtained in a 
concentrated solution before treating with the acid to be resolved, 
there would be greater chance of the complete resolution of the 
acid. 
It is almost certain that the failure to resolve mandelic and 
valeric acids completely is due to the fact that while the solu- 
tions cannot be evaporated on the water bath, yet at the ordinary 
temperatures the liquids have to stand so long before they are 
sufficiently concentrated for crystals to form that racemisation 
tends to take place during the process. 
This work was undertaken at the suggestion of Mr H. O. 
Jones, M.A., of Clare College. The author takes this opportunity 
of thanking him for the kindly interest shewn during the progress 
of the investigation. 
