Feature

Five Chemicals Seal Tiny Teeth Openings

[Photograph]: Maps Needed

Warmer and Drier November for U. S.

Predict Apples That Do Not Turn Brown in Air

H. T.’s Attackers Not Ill

Extreme Cold Key to What Makes Steel Really Hard

Tree Production Speed-up by Wires, Cutting Roots

Fluoridation Cuts Caries

Ozone as Preservative

Skin Resistance Measures Deafness in Children

Near-Vacuum Chamber Tests Supersonic Propellers

Replacement of Teeth