Physical Colloquium Meeting.

The first meeting of the Physical Colloquium was held in the Jefferson Physical Laboratory yesterday afternoon. Professor Trowbridge spoke upon the value of quartz vessels for use in spectrum analysis, and Dr. Lyman discussed the following recent papers upon radio-activity: Deviable Rays of Radio-active Substances; The Cause and Nature of Radio-activity, both by Professor E. Rutherford; and Experiments on Induced Radio-activity in Air, by Professor J. J. Thompson.