Scientific American Magazine Vol 197 Issue 4

Scientific American Magazine

Volume 197, Issue 4

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Features

Metropolitan Segregation

As Negroes move in from the South and whites move out to the suburbs a new pattern of segregation emerges in the big cities of the U. S., bringing with it significant economic, social and political problems

Morton Grodzins

Salt and Rain

What make the tiny water droplets of a cloud grow into the large drops of rain? Some recent studies indicate that particles of salt from the sea may play a key role in the process over both sea and land

A. H. Woodcock

Defense by Color

It is generally assumed that the coloration of some animals is for the purpose of deceiving predators. Is this assumption true? An account of some experimental efforts to answer the question

N. Tinbergen

The Sumerians

This gifted people lived at the head of the Persian Gulf roughly between 5,000 and 3,500 years ago. Their brilliant technological and social inventions laid the foundation of modern civilization

Samuel Noah Kramer

Plasmoids

These little pieces of plasma (a gas of electrons and ions) are created in the laboratory with an electrical gun. They have an unexpected capacity for maintaining their identity

Winston H. Bostick

The Specificity of Antibodies

Research is beginning to show how these body proteins "recognize" and react with particular foreign molecules and not with others that have very nearly the same chemical structure and properties

S. J. Singer

Congenital Deformities

It is now known that many of them are caused, not by hereditary factors, but by injuries during gestation. The kind of deformity is related to the time of early life at which the injury occurs

Theodore H. Ingalls

The Synthesis of Milk

How does a mammal make milk out of blood? The answer is sought by new experiments in which substances in the blood are labeled with either radioactive or nonradioactive isotopes

J. M. Barry

Departments

Letters to the Editors, October 1957

50 and 100 Years Ago: October 1957

The Authors

Science and the Citizen: October 1957

Mathematical Games

The Amateur Scientist

Books

Bibliography