Feature

Photocell Tests Smoothness of Polished Metal

Exercise Good for Teeth Theory Seems Contradicted

One Treatment Replaces Three for Diphtheria Protection

Insanity Gives Release from Hard Life

Occupational Tests Reveal Undeveloped Talents

Reorganization Threatens Occupational Testing Clinic

Setting Commercial Standards Relinquished by Government

Front Matter

British Anti-Cancer Serum Aids Human Patients

Bureau of Mines to Lose Fourth of Personnel

Mexican Treasure-Jewels Displayed in Chicago

Cancer Susceptibility Depends on Single Gene