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Scientific American Magazine Vol 216 Issue 4

Scientific American Magazine

Volume 216, Issue 4

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Features

The Social Power of the Negro

How is it that immigrants such as the Irish and the Italians have been able to evolve group power in the U.S., whereas Negroes have not? The principal reason is an unrecognized disunity among Negroes

James P. Comer

The Induction of Cancer by Viruses

Normal cells cultured in glassware can be transformed into cancer cells by several viruses. Such "model" systems are studied to find how the virus, with fewer than 10 genes, can produce the change

Renato Dulbecco

The Changing Helicopter

The unique capabilities of this improbable flying machine make it adaptable to many purposes. Because of recent improvements future models will have more speed, maneuverability and carrying capacity

Alfred Gessow

The Antiquity of Human Walking

Man's unique striding gait may be the most significant ability that sets him apart from his ancestors. A big-toe bone found in Tanzania is evidence that this ability dates back more than a million years

John Napier

Neutron-Activation Analysis

This powerful analytic tool is now routinely used in a wide range of disciplines to measure the concentrations of trace elements, often in amounts less than a billionth of a gram

Werner H. Wahl, Henry H. Kramer

Rivers in the Making

In various parts of the world water drains from the land not in distinct streams and rivers but in strangely interlaced channels. It seems that such drainage is a stage in the evolution of rivers

H. F. Garner

The Evolution of Bee Language

Different species of bees communicate In different ways. When primitive bees are compared with more advanced ones, it seems that communication by sound preceded communication by dancing

Harald Esch

Antimatter and Cosmology

Experiments in high-energy physics have demonstrated the complete symmetry between particles and antiparticles. A novel theory of the universe that takes this basic symmetry into account is advocated

Hannes Alfvén

Departments

Letters to the Editors, April 1967

50 and 100 Years Ago: April 1967

The Authors

Science and the Citizen: April 1967

Mathematical Games

The Amateur Scientist

Books

Bibliography