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Toxic Substances and Ecological Cycles

Radioactive elements or pesticides such as DDT that are released in the environment may enter meteorological and biological cycles that distribute them and can concentrate them to dangerous levels...

By George M. Woodwell

The Heart's Pacemaker

A group of specialized cells regulates the fundamental rhythm of an animal's heart. The pacemaker also limits the heart's range of responses to the influences of nerves and hormones

By E. F. Adolph

Ancient Ararat

Sometimes called Urartu, it was a powerful nation of the region around Mount Ararat in 800 B.C. A mound in Turkey has yielded much information about this nation and its widespread influence...

By Tahsin zg

The Surface of the Moon

Nine spacecraft have provided thousands of closeup pictures of the moon. Although they have revealed much never seen before, they have not solved the riddle of the moon's nature and origin...

By Albert R. Hibbs

Behavioral Psychotherapy

Abnormal behavior can be thought of not as a symptom of a hidden illness but as a problem of "social learning", and can be treated directly by methods of that are derived from principles of learning...

By Albert Bandura

Salt-Water Agriculture

Experiments in Israel indicate that many plants can be irrigated with salty water, even at oceanic strength, if they are in sandy soil. The technique might open much barren land to agriculture...

By Hugo Boyko

The Origin of the Automobile Engine

The first internal-combustion engine to operate successfully on the four-stroke cycle was built in 1876 by Nicolaus August Otto. His "Silent Otto" was a good machine with a poor theory

By Lynwood Bryant

Advances in Superconducting Magnets

In the past five years superconducting magnets have developed from a laboratory curiosity into the most practical means of generating intense magnetic fields for a growing number of research projects...

By Myron Strongin, Paul P. Craig and William B. Sampson


  • 50 and 100 Years Ago: March 1967

  • Science and the Citizen: March 1967

  • Letters

    Letters to the Editors, March 1967

  • Recommended


  • Mathematical Recreation

    Mathematical Games

  • Amateur Scientist

    The Amateur Scientist

  • Departments

    The Authors

  • Bibliography

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