SCIEMTIFIC.

Otago Witness, Issue 1966, 29 October 1891, Page 45

SCIEMTIFIC.

—The nature of the little organism wbioh in the blood produces ague and malaria fever, has (writes a B.Sc. in the Adelaide Observer) been made out b«tter than heretofore by an English surgeon. He has bucceecled in isolating it and cultivating it artificially with interesting results. Hitherto the organism,|in contrast to the 'bacteria of other infectious diseases, has been regarded as an animal, the bacteria being considered to be vegetable; but Surgeon Evans proves by his experiments that the organisms can be induced to go through the stages of development of a .highly organised fungus. It will be of great interest to see whether this minute fungus will be detected in the coil of malarial districts, for it is of great importance to find out in what way the malarial germs enter the human system, and a knowledge of this may lead to an investigation of the forms under which the diseased microbes generally pass their existenoe outside of the human body. — Water in its various forms is known to be one of the chief active ag6nts in wearing, wasting, and changing the face of the earth, but its action is almost completely absent in the cases of great deserts such as the Sahara. But other, forms of denudation are active there, amidst the mass of shifting sand, bare rocks and arid cliffs, nor is water itself entirely i absent, as Professor Walther has recently pointed out. He says that no part of the African desert is absolutely rainless, and as the storms, though rare, are heavy the mechanical effects of water are more marked than they would be were the rainfall more equally distributed. Variations of temperature are the most potent factors of waste' in such rainless and desert districts. The rock, uncovered by soil or plants, is completely exposed to such changes, and owing to the dryness of the air the temperature passes very rapidly from one extreme to another. The daily range of temperature in the Sahara may be 30deg Cent., and the yearly range as much as 70deg Cent. These changes, of temperature cause constant expansion and contraction, by which the rocks are split up into' fragments, ultimately adding their substance to the accumulations of sand. The sand itself, driven by the wind, has a great wearing action, and carves the faces; of cliffs and isolated outstanding masses or pillars of rock into fantastic shapes. Tabular hills, which may be large outlying portions of an extensive plateau, or small elevations of a few feet in height, are peculiarly characteristic of desert denudation, and are the result of a harder structure at the top, which preserves the softer material below. There is much evidence to show that the Sahara was once a 3ea-bottom, and many deserts are areas Buch as that at present in progress in the Aralo-Oaspian area, the Great Salt Lake of Utah, and the Dead Sea, these sheets of water being manifestly remnants of freshwater lakes of vastly greater extent, and are themselves being gradually dried up. Mr J. L. Bain says : "jit is well known to the m«dical profession that every mental effort causes a rush of blood to the brain, and that the amount of blood depends on the " intensity of the thought; but rush of blood means a rise in temperature, and if we could measure this we would be able to determine, in a rough way, the •• power" necessary for the generation of any thought or mental

effort; I accomplish this object in the following manner :— I have a head gear of some light, high-conducting (heat) substance. In its middle or any other convenient position I fix a thermo-electric pile, and connect this> b^means of flexible wires or otherwise, to a sensitive galvanometer. The extreme sensibility of the thermo-electric pile is well known, and therefore whatever rise in temperature takes place, consequent to the rush of blood, would be instantaneously indicated by the galvanometer. The utility of such an apparatus may not appear at first sight of great importance, but if we consider for an instant the facility or difficulty with which children at school learn their lessons, any doubts we may have entertained as to its practicability will be immediately dispelled. By .such a contrivance we could ascertain the " brain power " of boys and girls, nay; even men, and thus be in a position to indicate in what direction their mental efforts ought to tend." — The difference between a girl's throwing and a boy's is substantially this : The boy crooks his elbow and reaches back with the upper part of his- arm about at right angles with his body and the forearm at 45deg. The direct act of throwing is accomplished by bringing the arm back with a sort of snap, working every joint from shoulder to wrist. The girl .throws with her whole arm rigid, the boy with his whole arm relaxed. Why this marked and unmistakeable difference exists may be explained by the fact that the clavicle or collar-bone in the female anatomy is some inches longer and set some degrees lower down than in the masculine frame. The long, crooked, awkward bone interferes with the full and free use of the arm. This is the reason why a girl cannot throw a stone. —■The question, What is the state of the interior of the earth? has always been a fascinating one, which geology has only partly answered for us. Our knowledge of this subject may possibly be increased by a boring which is now being made at Wheeling, West Virginia. It seems that a well has been driven there to a depth of over 4000 ft, the object being the discovery of petroleum or natural gas. During this boring, a dozen thick veins of coal have been passed, while both petroleum and gas have been struck, but not in paying quantities. Gold quartz, iron ore, and other minerals have also been brought to the surface. Great interest has been taken in this boring by the officers of the Geological Survey at Washington, and the boring is to be continued under present .auspices until it reaches to the depth of one , mile. After this the Government will take up the work, and the drilling will be continued into the earth as far a3 practicable, not for the procuring of any particular natural product, but for scientific purposes, and in order to ascertain the thermo-metric and magno-metric conditions. —In a paper on " The Ignis Fatuus of Photography," F. Adolphe mentions the following as among the specialties which modern scientists and chemists are seeking as a means whereby their results may be indirectly transmuted into gold: — The artificial production of the diamond from carbon, which means the crystallisation of carbon ; prevention or cure for epilepsy and consumption; the complete consumption of coal, of which but 5 per cent, is now available ; ' photography in natural colours ; the direct j utilisation of solar heat, and the ebb and flood ; the production of " attar of roses " from some worthless substances. Even the alchemist's original dream of direct and genuine transmutation is being revived, for the indications are increasing that the present elements are nob the simple substances they have been supposed to be, and should gold prove to be a compound, its artificial production would be but a question of time. — Dr Bruckner in his great work on the variation of climate shows that climate has not undergone any continuous variation from the earliest historic time, but that it oscillates, showing alternate periods of heat and cold, and of dryness and humidity, the period being about 35 years. — The Tilbury Cement Company, at their works near Tilbury Docks, London, are now manufacturing, under the patent of their general manager, Mr David Wilson, such varied and unlikely, articles as telegraph poles, railway sleepers, gate posts, water pipes, water tanks, -pulleys, sheaves, paving, grindstones; Sec, ice. The material thus adapted to such diversity of purpose really forms a concrete, in. which wire rods or netting -form the .most important constituent. In the circular articles the wiie rod forms the strength-giving core', and in flat or tubular articles the netting fulfils that function. In the poles and posts especially, homogeneity, flexibility, great strength, and, above all, durability, are the merits claimed, The resistance to wear and decay, from either climatic or chemical influences, presented by the cement surface is not the least valuable of the properties possessed, by this novel combination of common materials. —The gradual lengthening of human life is among the achievements of modern civilisation. It suggests that a vigorous old age may be in a considerable degree dependent upon personal conduct, and Dr B. W. Richardson advises that parents give their children a start in the most favourable conditions by protecting them from mental shocks and unnecessary griefs, and making their surroundings as happy as possible. The persons themselves, when older, should avoid grief, and eschew hate, jealousy, un* chastity, and intemperance, aU of which hasten the coming of old age. When old age has really begun, its progress may be reduced to a minimum by securing the least friction and waste. Rules for this include subsistence on a moderate quantity of light but nutritious food, varying according to the season ; dressing warmly but lightly to preserve an even temperature; keeping the body in fair exercise and the mind active and cheerful ; maintaining an interest in the world's affairs, and taking a reasonable share in its labours and pleasures ; securing plenty of sleep at proper hours in a comfortable room, and avoiding passion, excitement, and luxury. Thoughtful living in this way may enable a weak man to outlive his robust but less wise neighbour.

Far more than 40 yearsJAyer's Cherry Pectora tasi been iucceisfuliy preioribed In oaiei of consumption. Ihii medioine always affords great relief in pulmonary diiemei. Aik your druggist for it.