SCIENTIFIC MISCELLANY.

Otago Witness, Issue 3713, 12 May 1925, Page 67

SCIENTIFIC MISCELLANY.

(For the Witness.) A MACHINE CLEANING PISTOL. A compressed air pistol, w'ith a trigger controlling a spray of kerosene or gasoline, ia a novel device for cleaning automobile gears and other machinery parts. It may be used also for applying thin paint, whitewash, insecticides, or such wood preservatives as creosote. RIVER WATER AS A GERMICIDECertain French rivers are found by Dr Arloing of Lyons to have a strong destructive action on intestinal bacteria. The Rhone and Isere have a marked effect on typhoid organisms, other rivers are unfavourable for paratyphoid and dysentery bacteria, the effects varying with the source of the water. ANCIENT MAGNIFYING GLASSES. Small glass lenses may have been used 6000 years ago, according to Professor W. E. S. Turner, of Sheffield University. Cuneiform inscriptions in Chaldea were perfectly formed, though so minute as to be illegible to the naked eye, and in the ruins Layard also found the tools with which the inscriptions were made, as well as small lenses of glass. MOISTURE ABSORBED BY COAL. The wetting of coal is fonnd by the U.S. Bureau of Mines to be a possible source of considerable expense to consumers. Little weight is added to the larger sizes of coal, but the smaller sixes of both bituminous and anthracite may retain moisture up to 20 per cent, of their weight, as high as 12 per cent, seeming to be not unusual. Coal with as much as 10 per cent, of moisture may appear quite dry. LIGHT FOR COAL MINES. The electric cap-lamps used in United States coal mines are estimated to number 200,000, although in 1911 the Pennsylvania bituminous coal mines, producing 6b per cent, of the country’s soft coal, had about 45,000 Hame lamps, with no electric lamps. *The Bureau of Mines reports, however, that the flame safety lamps, which have so effectively served for more than three generations, cannot yet be wholly discarded. The flame warns the experienced miner of a dangerous rise in explosive gases, and its going out indicates that the air’s oxygen is too low for safe breathing. MARINE LIFE IN THE SUEZ CANAL. Novel and interesting life conditions exist in the Suez Canal, which not only connects two seas of quite different fauna, but as nearly a third of its 85 miles of length includes the two so-called Bitter Lakes, which contain salt deposits giving the water a- high degree of salinity. This zone of very salt water has been supposed to serve as" a natural barrier keeping the life forms of the two seas separate. An expedition of four Cambridge biologists has made the surprising discovery that not only is this not true, but that this section of the canal is richer in marine life than either end. Such forms as soles, grey mullet, and certain sea worms are both more numerous and larger than elsewhere. FAT IN BRUISES. In a contusion or bruise the crushing force damages the fat in the skin and subcutaneous tissue rather than the true skin’s dense fibrous tissue, according to Sir Bernard H. Spilsburv to the Medical Society of London. Blood forced by capillaries and veins from their torn ends is infiltrated into surrounding parts, and similar hemorrhage may be produced in underlying loose connective tissues, muscles, and viscera. In more severe cases the soft tissues beneath the skin may be pulped and disorganised, when profuse bleeding from torn .arteries may push aside the crushed tissue, forming a hematoma or blood tumor. In the eyelids and other parts having skin of loose texture, blood infiltrates readily, bruises developing rapidly, but where the deeper skin is more densely fibrous, and fat is scanty or absent, as in the palm of the hand, greater violence is required to produce a contusion, and little blood is effused. Some persons bruise very readily, a likely explanation being that with insufficient exercise and much soft fat, like butter, in their diet, the fat deposited in the subcutaneous tissues has a low melting point being more than usually fluid, and easily cruffied at body temperature. The trained athlete is not bruised by fairly severe blows, his skin being “ hard,” like his muscles. PSYCHOLOGY IN INDUSTRY. Inefficiency in the worker is attributed by Dr C. S. Myers, of the British National Institute of Psychology, to three chief factors—needless effort, insufficient interest and attention, and irritation. The first is mainly due to such conditions as defective arrangement and appliances of the plant, poor lighting and ventilation, and Dad halfits of posture and movement. Plant and machines, mechanically satisfactory, may be poorly adapted from a physiological and psychological standpoint. An improved implement in a margarine factory reduced the worker’s movements 16 per cent., and his production time 13 per cent.; improved arrangement of material and better distribution of work increased output an average of 26 per cent, in eight- departments of a large industry; and improved illumination gave increases of 10 to 14 per oens. in production. Better instruction of the worker gave both increased production and leSvsened fatigue. A number of novices trained by the institute yielded 21 per cent, greater production than a like group trained by the employing company: and study of movements and appliances In another industry brought an increase of 36 per Cent, in output, with on expression of approval from workers whose fatigue was greatly lessened. Better Interest and attention are secured by more careful selec-

tion of workers, suitable incentives and supervision, and avoidance of too long working periods. Irritation may be due to & feeling of injustice, or to needless flurry or waiting; and in two plants breakage was reduced 63 and 40 per cent, by removing the source of irritation and improving the handling of fragile material. THE ASPARAGUS OF THE ORIENTALS. Edible shoots of bamboo, so much eaten in China and Japan, develop from underground root stalks, often reaching a weight of several pounds, especially when banked up to increase their length. They are out oa their tips appear above ground, and the tough sheaths being stripped off the wliite inner portion is found in the tender stage required for cooking. The favourite species for vegetable garden cultivation is stated to be the Phyllostachys mitis, the “ moss chiku ” of the Japanese. It- is not one of the largest bamboos, some of which may attain a height of 120 ft, but when left to grow unchecked this plant may reach a height of 50ft or more, with a diameter of stem of 6in. The plantation for food purposes may be cut back when about 12ft tall; then the branches spread, out in a low canopy, while an abundant crop of small root shoots takes the place of the less desirable and fewer shoots of the unpruned trees. In its unchecked growth the plant may develop to a height of 20ft in six or seven weeks, a growth of a foot or more in 24 hours being not uncommon. When half or two-thirds grown the successive joints of the plants begin to shed their sheaths, and the highly-polished green canes appear. The sheaths are collected for making sandals, hats, and other objects. The young shoots are eaten in a variety of ways—sometimes boiled in small pieces m salted water, sometimes frietj crisp in thin strips in peanut oil, or used in soups or stews, or salted and served with rice and butter. They are also pickled and candied, and to some extent are canned for export to American and other cities.