Feature

Spinach Over-Rated as Source of Iron

Mockingbirds Are Upholders of Property Rights

Reading Improves Spelling, Even for Words Not Read

Nature Ramblings: Overworking Our Mother

To Improve Mayan Farming Used Thousands of Years

First Glances at New Books

Front Matter

American Scientists Take Part in Physiological Congress

Windpipe’s “Lid” Not Used during Swallowing of Food

New Type Boiler May Bring Great Changes in Navies

Seven-Point Plan Offered for Mineral Conservation

[Photograph]: Steam’s Answer to Diesel