Jor detecting Metallie Masses in the Human Body. % 
at intervals can be substituted for the microphone with 
advantage. 
0 iy 
4 
balance was most suitable for my purpose, and I immediately 
Commenced the construction of such an apparatu 
Suggestions tested.—Just at this time Il learned from the news- 
papers that Prof, Simon Newcomb, of Washington, had the 
Be: 
i 
