Scientific.

New Zealand Mail, Issue 360, 4 January 1879, Page 9

Scientific.

SCIENCE GOSSIP. (From the Melbourne Leader). A great deal of seeming wisdom, but in reality downright nonsense, has been written from time to time, and is still being written, about the relations between trees and light- ! ning. One of the latest dicta is th it " the best conductor for a house is a lofty tree." If there be any truth in this it is nullified by the want of precision. If . the tree overshadows the house it is likely enough that the lightning will discharge itself into the top branches of the tree rather than on the house itself; but even if it does so, the house will not be necessarily safe, for the shortest way to the ground may be through the bouse itself. If the tree be at a distance from the hou-e it is about an even chance that the house will be first struck. The lightning is, it is said, a respecter of trees, if not of persons, giving a preference to the poplar, the aspen, aud the oak, and neglecting the beech and the fir. This is pure imagination, and every idea of tht* sort is based on a very few, perhaps single, observations. I once travelled with tw«> farmers who, during a heavy thunderstorm, entertained me with all the country learning they could muster on the subject. Ttiey be ieved that there wa3 a great deal of iron in oakwood, and that this attracted the lightning. They further had an idea that there was always a strong draught under the branches of the oak, and that the lightning was drawn in by this draught. They wound up their scientific di.-quisition by the clincher in the shape of a wi-e saw:— Keep away from the oak and creep under the thorn, Or you'll be killed as sure as you're born. This is quite as good science as the more pretentious article that is often offered. To creep under the lee-side of a hedge duriug a thunder-storm is moreover good advice. Pro- ! fessor Calladon believes in the susceptibility of the aspen, because he knows of "one" which was struck on the shore of the Lake of Geneva, while taller trees of other sorts escaped. It was, moreover, struck low down on the trunk, the upper branches being uninjured, from which he iufers that the branches are good conductors, aud the trunk, " from its containing more sap," a bad one. This sap, he moreover thinks, is converted into steam, so that the trunk explodes, like a boiler. Would he be surprised, I wonder, if he weie told, that it is the wet outside of the branchethao is the conductor, and that the " stroke" takes place when the dry trunk is reached that it is the solution of continuity of the wet (surface that causes the catastrophe. It is, moreover, by no means a certainty that lightning strikts invanably downward. There is no reason why it should not at least occasionally leap from the earth upward. Knowing, as I do, that the flash is instantaneous, I -peak with all reserve when I declare th »t since I first deliberately tried to observe the oour.-e of a flash of fork lightning, I have never seen one strike downward Sometime the flash is from cloud to cloud, aud sometimes from the eaith to the cloud. I aak my readers &o watch and

form their own judgment I do not say that their experience will be the same as mine, but I am not subject to optical delusions, and the instantaneousness of the flash is just as much in the way of seeing ib strike down as up. Darwinism, from being threatened, first with persecution and then with neglect, is in a fair way of being smothered from being made too much of. The theory of evolution aud development is lugged in to explain all sorts of things with which it has nothing to do. In Germany they are riding the hobby to death. At the last session of the Congress of Naturalists and Physicians, held at Cassell, two papers were read, one on the " Relations of Darwinism to Social Democracy," and the other on the " Relations of the Physicist to the Natural Sciences." The relations between Darwiuism and Democracy must be as far-fetched a-s those between the megatherium and Jack the Giantkiller. If ever Darwinism falls iuto discredit, it will be from the mistaken zeal of such meatus Professor O-car Schmidt, the author of the first of these paper-. After listening to his oration, the congress adjourned for a week to digest the strong meat aud to make preparations for the work in the sections If Darwiu has anything to do with social democracy, he had better keep out of Germany, otherwise the pains and penalties cf the new Bill may overtake him. A scheme f<.r a Vesuvius railway, similar to that constructed for the ascent of the biighi, has been approved by the Superior Council of Public Works at Naples. A discov. ry, which may possibly turn out to be one of great importance, has just been made in America. It is that good sugar can be made from the stalks of Indian corn. The matter is considered of such general interest that the Government of the United States has tekeu the matter up, aud the Agricultural Department is carrying out experiments to determine whether the manufacture on a large scale would be commercially profitable. The German Minister of Instruction, in a recent report on the influence of gaslight on the eye, concludes that no evil resul s follow a moderate use of gas, if the direct action of the yellow flame on the eye is prevented. Grave objections he makes to zinc or lead shades, most evils affecting the eye being traceable to them. Their use, it is said, inevitably tends to blindness or inflammation, and other harmful effects. The milky white glass shade is the best, as it distributes the light and has a grateful effect on the eye. The burner should not be too close to the headj as congestion of the forehead and headache results from the radiated heat. The gluss plate below the gas is especially useful for the purpose, as it causes an equal distribution of the light—necessary where a number are working at one burner prevents the radiation of heat, and tends to a steady illumination by shielding the flame from ; currents of air. In cases* of highly iuflarnad eyes, he recommends dark blue globes.