A PILGRIM WORSHIPS

The most striking, even dramatic, nature photographs are usually posed quite unconsciously. A short time ago, during the autumn migration of praying mantises that usually follows the first chill weather, one of these strange insects blundered through the open window of the Bell Telephone Laboratory in New York City and alighted on the base of one of the new dial telephones. It rested there, in its spectral pose, long enough for one of the studio photographers to set up his camera and "shoot" the picture reproduced on the cover of this issue of the Science News-Letter.

TEST RADIOACTIVITY

With a market flooded with waters, salves, hair tonics, tissue creams, mouth washes, heating pads, and other preparations alleged to have great healing power because of their radioactivity, government chemists are working on suitable means of detecting the presence or absence of radioactive substances in water and drugs.

At the meeting of the Association of Official Agricultural Chemists, J.W. Sale of the U.S. Department of Agriculture reported on one method of testing radioactivity. He recommended further checking of the method by chemists, before official adoption by the association.

The discovery of the curative properties of radioactive substances has resulted, among other things, in the production of solid, semi-solid and liquid preparations which are being sold as possessing sufficient radioactivity to cure all kinds of conditions. A recent government survey of such waters and drugs revealed that their medicinal efficacy was much misrepresented. Action will be taken against shipments of the alleged radioactive products which are falsely or fraudulently misbranded.

Radium and radioactive substances have possibilities of great harm as well as great good, it is declared. Using them indiscriminately without adequate supervision is extremely dangerous.

NEW ROBOT A TIRELESS COUNTER

Much of the wearisome, routine, midnight-oil work that now besets biologists and other scientists will be taken off their hands by a new electrical robot described at the meeting of the National Academy of Sciences. The device is the invention of A.L. Loomis, banker-scientist of Tuxedo Park, N.Y., and has been given its first extensive workout by Prof. E.N. Harvey of Princeton University.

The mechanism is intended for the recording of natural rhythms, such as breathing, the beating of a heart, or the rapid impulses along a nerve trunk. It is geared in such a way that ten successive beats are recorded by a straight line drawn by a pen, the length of the line indicating the time of the action. Then the pen goes back to the zero line and starts recording another ten beats, on a line parallel with the first. The instrument will keep this up for hours or days on end, so long as ink, recording paper, and the pulsating animal or organ hold out. In the meantime the scientist who used to have to sit and watch his experiment through many weary hours can lecture to his classes, or play golf, or go home to bed.