SCIENCE NOTES.

New Zealand Herald, Volume LXIII, Issue 19454, 9 October 1926, Page 5 (Supplement)

SCIENCE NOTES.

ANCESTORS OP MANKIND. STOOPING POSTURE THEORY. VALVES IN VEINS. Hidden away in the interior of man's veins are indications that his ancestors once walked in a stooping position, according to Dr. C. W. Stiles. In the veins of human beings, as well as of (he lower animals, Dr. Stiles stated, there are numerous little check-valves, that relieve the back-pressure of the blood and prevent it from flowing the wrong way. In all cases in animals these valves are found in veins where the blood commonly flows "uphill" toward the heart, as in the veins of the legs and arms. In animals the blood must flow "uphill" also in the veins that lie beneath the ribs, •since the animals carry the trunk of the body horizontally and the ribs therefore hang vertically. But in the veins that run horizontally, notably the great trunk vein that runs along beneath the backbone, no valves aro needed to prevent back pressure, and none arc found in this position. In man, however, the trunk is carried vertically, so that tho relative positions of the veins are exactly opposite to those in the animals, the rib-veins being horizontal instead of vertical and the great vein of the back being vertical instead of horizontal. Yet the valves in human veins follow tho same pattern as do the valves in animal veins. They are found in tho rib-veins where they are not needed and are absent from the great dorsal vein where they would be really useful. A writer in Popular Science remarks:— " This is understandable on a theory of ancestral survivals in man, but is completely contrary to a special-creation theory which assumes that the body of man is perfectly adapted for his present mode of life and made without any useless parts or any mistakes." MUSTARD OAS. Mustard gas is the popular name for an asphyxiating chemical introduced by I lie Germans in the later stages of the Great War, and subsequently adopted by the Allies. It contains chlorine, carbon, hydrogen, and sulphur, and is known chemically as dichlorodiethyl sulphide. It was first prepared in 1854. Its popular name is due to its effect m raising blisters 011 the skin as mustard does.

SUN'S DISTANCE FROM THE EARTH. The sun's distance from the earth is measured by trigonometry during the transit of Venus across the sun's disc and by complicated experiments in the velocity of light. Both give approximately the same mean distance, namely 92,965,000 miles. LIMIT TO THE STAR'S SIZE. The source of. the meteors which pass through the earth's atmosphere is ex plained by some recent conclusions of a noted British scientist who says that a star whose mass is 50 times that of our sun has reached its limit .in greatness. Stars of greater mass than this cannot exist; they would burst of their very enormity. Their own pressure from within, combined with the centrifugal force of rotation, would over-balance the force of gravitation, and they would fly apart in billions of fragments. FLOW OF NATURAL GAS. I'ipes inserted in the ground may bring Johannesburg all the gas required for commercial and domestic purposes. Oil prospectors sunk a 600 ft. shaft fifteen years ago at a spot sixty miles from the. city, but a sudden rush of gas caused operations to bo abandoned, and the shaft was forgotten. It has now been discovered that gas has been flowing steadily over since, and has killed all vegetation in the neighbourhood. A financial company has now covered the top of the shaft, only allowing the gas to escape through a small jet, which, when lighted, gives a flame 40ft. high. Leading experts say they believe that an inexhaustible supply of natural gas has been discovered, which is perfectly pure, and only needs conveying to the city. Tests show the gas to give twice the heat of coal and six times the heat of ordinary commercial gas, and a movement is projected to sink more shafts. Mining engineers affirm the belief that the gas indicates a rich oil deposit. /PREVENTING RUST ON TOOLS. All good mechanics desire to keep their tools free from rust. Many methods are in use but all do not serve the purpose equally well. Calcium chloride, for example, will absorb all the moisture in a tool cabinet, hut it soon becomes a saturated mass, which does more harm than good. However, a positive cure for the rusty-tool evil, which is very simple, is to place 10 or 15 penny-worth of animal charcoal—obtainable in any chemist's—in a small tm box that has small holes drilled 'through the cover, and put it in the tool chest. It will absorb all the moisture without being dissolved, and when it can absorb no more', turns to a grey colour, warning the user that it should be replaced with new charcoal. Replacement is needed only at long intervals, however.