From the December 9, 1933, issue


Psychologists were amazed by a motion picture film given a private showing for them recently in Chicago. The film showed a little baby less than a year and one-half old doing the most surprising feats of muscular skill. He roller-skated like a miniature master of the art. He climbed off stools of much greater height than his own. He walked up steep inclines with perfect aplomb. And he swam under water without support or with slight support he swam on the surface like a budding Weissmuller.

But the picture did not originate in Hollywood, and this baby is not being exploited for his amazing abilities. He is one of the subjects in a psychological experiment being conducted at the Normal Child Development Clinic at Babies Hospital, New York City. There it was that the film was made.

The experiment is for the purpose of finding out what are the effects of intensive training on the development of the very young child. This little boy has been carefully and intensively trained and exercised from the time he was but 20 days old. His twin brother, for purposes of comparison, has been brought up in the ordinary routine of the modern infant–no systematic exercise, no unnecessary handling, mainly just peace and quiet in his crib.


In discussing the significance of the paper on the expanding universe, presented to the National Academy of Sciences by the Abbé Georges Lematre, Dr. Harlow Shapley, director of Harvard College Observatory, mentioned that some recent observations of his own had materially reduced the current estimate of the rate at which the cosmos is “exploding” and as a consequence its estimated age as well. The universe, at least that part of it we now know, does not need to be less than five billion years old, he said.

A still more dizzying figure was one which he gave as a very rough and tentative estimate of the density of matter in the greatest “supergalaxies”–vast aggregations of spiral nebulae, each individual nebula containing billions of stars as big as our sun or bigger. Despite this tremendous massing of matter, Dr. Shapleys estimate of its average for all the space occupied by such a supergalaxy in grams per cubic centimeter is represented by a fraction written as 2 over a 1 followed by 28 zeros. And this, he said, is very much thicker distribution of matter than that which exists in the space between the supergalaxies.


Explosions of “safe” dry cleaning fluids have added another hazard to home dry cleaning efforts. Some of the so-called safe solvents sold for home use have been found to be decidedly unsafe. Fluids demonstrated to have been perfectly safe when first used have exploded after being used a few times.

This contradictory behavior has been simply explained by the results of laboratory experiments. These dry cleaning fluids are made up of regular cleaners naphtha to which has been added enough of an inert solvent, carbon tetrachloride, to make them nonflammable. One-half carbon tetrachloride and one-half naphtha make a suitable mixture.

While in use the carbon tetrachloride evaporates more rapidly than the naphtha, thus leaving a mixture rich in naphtha and hence explosive. Experiments show, for example, that when 37 percent of a total mixture originally composed of 43 percent carbon tetrachloride and 57 percent naphtha had evaporated, there remained a mixture made up of 29 percent carbon tetrachloride and 71 percent naphtha–a decidedly unsafe product.

Fluids made up entirely of carbon tetrachloride or other nonflammable solvents remain safe indefinitely.

From the Nature Index

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