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BARRY I.L.P.

H SNAP-SHOTS. 11

Purity Crusade at Barry.

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YANKEE HUMOUR,

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THE NAMING OF FORGET-ME-NOT.

SCIENCE NOTES AND NEWS.

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SCIENCE NOTES AND NEWS. HOW AURORA ORIGINATED. In a discussion as to the scientific causes of aurorse, a correspondent writes to the Scotsman that the most probable explana- tion seems to be that they are produced by electrified particles of matter which have been shot out from the solar flames or prominences. In these prominences great sheets of glowing gas are being driven up- wards with at least 500 times the velocity of a cannon ball, and some of the more highly- electrified particles may travel with a velocity that is vastly greater. GOUT AND CANCER. Dr. S. Monckton Copeman, in dealing with the question of cancer, before the British Association, said that of individuals at pre- sent living above the age of thirty-five, one in eight women and one in twelve men would eventually die of cancer. In certain industrial occupations the mortality was very much greater, to the extent of 100 per cent. among chimney sweeps, although, of course, they no longer climbed chimneys. He de- clared that sufferers from gout were very unlikely to contract cancer, as the two tfcseases were antagonistic. Cancer was con- stitutional, and gout local. SCIENTIFIC PLANT FORCING. The best natural conditions for plant growth are artificially supplied in one of the greenhouses of the Royal Botanic Gardens. On cloudy days an artificial sun, in the form of a water-surrounded arc-lamp automati- cally moved along a tramway, sends light in the natural way to every part of the plants. Earthenware pipes from the engine diffuse a carefully regulated supply of moist air charged with carbonic acid, iron pipes distri- bute heat to keep up the best temperature, and an electrostatic machine stimulates the soil to convert insoluble into soluble nitrates, and arouses the roots to the highest degree ol activity. SCOTTISH PEAT MOSSES. An investigation in Scottish peat moese* by Mr. Francis J. Lewis elicits the fact that in the southern uplands the stratified plant remains shew a gradual change from a wood- land condition, to that of heath and moss, and then back again to woodland. In some locali- ties a bed of Arctic plants is interposed be- tween the two woodland ages. A correspond- ing sequence of the beds in widely separated areas is considered as furnishing evidence of varying climatic differences during the deca- dence of the Glacial period. Arctic plants are everywhere absent from the base of the peat, which consists of a forest bed contain- ing birch and hazel remains. RESPIRATION OF SEEDS. Experiments on the respiration of seeds in a dry or resting condition have been de- scribed by P. Becquerel in Comptes Rendus. Generally speaking, seeds in the dry state, when kept in the dark, give off a trace of carbonic gas, and absorb a small amount of oxygen. This gaseous exchange is greater when the seeds are exposed to the light, owing to its power of favouring oxidation. The testa of the seed is an important factor in determining the rate of respiration. In Ricinus the gaseous exchange was higher in the testa alone than in the seeds from which they had been removed. Dehydration also plays an important part, and in some in- stances no gaseous exchange took place in the absence of moisture. THE SIZE OF THE COMING RACE. Sir Victor Horsley, at a meeting of the British Medical Association, spoke in favour of making a system of periodic measure- ments part of the general scheme of medical inspection of school children. It was stated that at Marlborough School, where annual measurements have been recorded for twenty years, the average size and weight of the beys has been steadily increasing. From a comparison of these statistics it appears that in 1906 the boys fourteen years old were about 51b. heavier and nearly Iiin. taller than those of the same age in 1886. The eixteen-year-old boys of the present date keep up in proportion. NITROGEN-FIXING BACTERIA. A peculiarity about nitrogen-fixing bac- teria is that they grow and form colonies only on leguminous plants. The agriculturist, in order to enrich the soil with nitrogenous matter for a crop of cereals, for example, must grow a crop of beans, peas, &c. It ap- pears, however, says the Globe, that under certain conditions the required bacteria can be induced to grow in other host plants. The subject was discussed at the meeting of the British Association, and Professor Bottomley communicated the results of some recent ex- periments. Cultivating some nitrogen-fixing bacteria first of all in tomato juice, he after- wards inoculated tomato plants with the cul- ture. These plants produced a greatly-in- creased yield. Professor Bottomley has also succeeded in inducing bacteria to establish themselves in the cortex of the roots ol wheat, though they produced no nodules aQ they do in leguminous plants. COLLODION IMPRINTS OF FOSSILS. The difficulty of studying the minuter structure of fossils is increased by their oftem fragile nature, which prevents sections being made for the microscope. Even when the fossil is well preserved in a hard matrix it is a laborious process to obtain a transparent section for microscopic examination. And at the best this method does not lend itself to the study of surface structure. Professor Nathorst's method of obtaining collodion im- prints of the surface structure of plants helps the geologist in this difficulty. To ob- tain the imprint collodion is dissolved it ether, and a drop or two is allowed to fall on the surface to be copied. The ether eva- porates rapidly, leaving a hard film in a few minutes. This is easily detached, and placed on a glass slip under the microscope. It is found to present a faithful copy of the minata structure of the original. NATURE'S STEELS. At a meeting of the Iron and Steel Insti- tute in Vienna, Professor Friedrich Ber- werth called attention to steels manufactured in the laboratory of nature. Comparing them with those of artificial make, he suggests that manufacturers may find one of nature's hints to inventors" in their further studv. Among those fragments of planetary matter which reach the earth from external space, and are known as meteorites, many are metallic, and composed chiefly of iron and nickel. And Professor Berwerth points out that recent researches have shewn that these metallic meteorites are essentially steels. Steels, as made in our steel works, are iron. carbon alloys, while the meteorites are iron and nickel alloys with meteoric carbon. Pro- fessor Berwerth thinks our steel manufac- turers might profitably imitate such natural steels. Meteoric iron and our manufactured steels are, he points out, results of essen- tially similar chemical and physical causes." And these natural steels are of great hard- ness and extreme toughness, qualities of the highest importance in steels. ANTS AND ULTRA-VIOLET RAYS. In Nature Notes Mr. O. C. Silverlock re- cords the results of experiments conducted by himself during two years with the view of testing the sensibility of ants to changes of temperature and to the ultra-violet rays of the spectrum. As regards the first point, the experiments indicate that very small changes of temperature are perceived by these in- sects, the sensations of heat in which must be much more delicate than in human beings. Many ants, for instance, perceive so small a rise of temperature as 0'3deg. C., while a very large percentage take cognis- ance of a rise of 0"5deg. C. In respect to the ultra-violet rays, it has been shewn by Lord Avebury that these affect ants like true light- rays, and this being so, the author is of opinion that these rays probably appear to them as a colour of which the human mind cannot form a conception. The ante do not appear to be chemically affected by these rays, but they change their positions when placed in the spectrum by reason of their dislike to the colour of these rays, and also on account of the smaller heating effect pro- duced by this end of the spectrum.

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