SCIENCE NOTES.

Otago Witness, Issue 2209, 2 July 1896, Page 48

SCIENCE NOTES.

*.' Repeated instances are said to have been noted in Germany of lightning flashes, instead of being attracted by the lightning conductor on a blast furnace chimney, taking the obarge of the chimney itself as a conductor, and passing down through the furnace charge, through the pig bed and into the earth, without doing any damage. It is said that this has occurred several times at one furnaco, where a good conductor extends above the top of the chimney, the explanation being that a column of smoke containing much water and, carbon dust extended up to a considerable height, and thus furnished a better conductor oE electricity to and through the charge itself than was afforded by the outside conductor.

• . • The United States Navy department has recently adopted a form of machine gun which is known as the "Oolt automatic," and it is made by the Oolt Company of Hartford, Oonn. It stands on a tripod, and has a weight of only 401b, so that a horseman can carry It in a boot behind his saddle, and even a bicyclist can mount one without much difficulty. This gnn will give a continuous fire of 400 shots per minute for an indefiuite time, and in a reoent test for accuracy, at 200 yds, made JOO'lnts on a target the size of a man, in 16 seconds. The cartridges are fed to the gun by a belt, and any kind of ammunition may be used. The expansion of gas during one discharge works the necessary mechanism for the next.

*,• While England is one of the worst vaccinated countries, it also is one in which the vaccination raises the greatest outcry when compulsion is attempted. We still maintain the old creed that vaccination from arm to arm is the true way to safety, while other nations by animal vaccination practically diearm objections to the operation. The first step then in the future of vaccination must be the universal substitution of animal for arm-to-arm vaccination; the next the securing of aseptic vaccination, for there is but little doubt that as vaccination is too often done at present it is an inoculation with a very mixed infection. But we are far from saying that these steps should be the last. Everything points to the possibility of our being abla before long to obtain pure cultures of the germa of smallpox as of other diaease3 entirely independent of any living media, and it is not unreasonable to balieve that when that result shall bo obtained vaccination will be a much less serious business than it is at present. Perhaps it is permissible to look ahead still further, and anticipate the time when even the inoculation of living germs, atteuQfitea though they be, may bo found

to be unnecessary, and when vaccination, instead of being the production of a disease, will consist essentially in the administration of a chemical substance produced by cultivation of the germ— a drag, in fact, which shall give immunity. This would indeed be a thing worth having. We now celebrate the centenary of a discovery which, while Ml of practical usefulness, has been of wondronely slow fruition in regard to science. Let us hop 3 that in the century now opening progress may be of quioker growth. — The Hospital.

' . ' In the Zurich Industrial Exposition an . air tester is exhibited, which shows whether and in what degree the air in a workshop is contaminated. The apparatus consists of an air-tight dosed glass vessel filled with a rod fluid. Tbroogh a glaes tdbe, that dips into the liquid and is bent at the top, a drop falls every 100 seconds on a cord that hangs beneath and that is somewhat atretohed by a weight. The fluid from which the drop comes has the property of changing its red colour to white by the action of carbonic acid. The more oarbonic acid there is in the air the quicker this change in colour takes place. If the air is very foul the drop becomes white at the upper end of the cord, while the change of colour corresponding to a flight proportion of carbonic acid does not take place till the drop has run farther along the cord. The exact condition of the air can be ascertained by observing a soalo that is placed alongside the cord and th&t is divided into convenient parts, bearing the designations, " extremely bad," " very bad," "passable," "pure." This is surely a very useful device, and should be found in every factory, every workshop, and every place where persons are orowded together, — Gaea (Leipsic).

'.* In order to save the sight oE one, perhaps both, eyes, when one was injured, a physician voluntarily shut himself in a room made totally v dark v for nine months. The fortitude which enabled him to adopt thia, course, and the ingenuity by which* he preserved his and faculties under the depressing obpditioas are sufficiently remarkable ; but he also kept a record of his impressions when he at last looked again upon the light. He found that in the nine months' dark cess his eyes had lost all sense of colour. The world was black, white, and grey. They had also lost the sense of distance. His brain interpreted the picture wrongly, and his hand did not touch the object meant to be grasped. Practice, however, soon remedied the last-induced defect of eight. Experiments with skeins of various coloured wool, in the presence of one who had normal colour-vision, soon restored his lost faculty.

• . • M. Flammarion, in the- course of experiments on the radiation of spectrum colours, has made gome interesting observations on sensitive plants. Four plants, sown the same day and of the same size, were placed under glaes, excluding respectively all but the red, green, and blue raya, the fourth plant being under ordinary white glass. At the end of six weeks the red plant was twice as high as any of the others, the green came next, then the white, while the blue had not grown the fraction x>i a centimetre. The red plant was healthy, but abnormally nervous, 1 curling np at a breath. The plant kept under white glass, exposed to the ordinary gun rays, though third in the order of growth, was vigorous and stout.— Scientific American.

'.' Lord Armstrong has recently made acme very carious phofco-eleotrioal experiments by means of a Wimshursfc machine. This machine 1 is caaaed to charge two large condensing jars, and the brush discharge from those latter, just before the tension rises sufficiently to produce an actual spark, is made to impinge upon a very sensitive gelatine plate. The operation is conducted in a dark room, and in the absence of either camera or lens, but the result on each plate employed is a most beautiful arborescent pattern, which is varied in each picture bj modifying the conditions of the discharge. Vtry beautiful effects are also produced by using a fcimple plate of glass which, after being waxed, is covered with a very delicate layer of fine dust; by the action of the discharge this dust is made to assume various curious figures. II; is well known that Nature endows the lowliest organisms with most perfeot form and intricate adornment, but it is curious to note that beauty of design should accompany even the phenomena connected with a discbarge of electricity. •.• The tourist who rashly trudges up Mont Blanc securely roped to a large party of travellerfl'is apt, if unused to such exercise, to feel sick, and at length to be sick, after two or three hours' climbing. He is ingloriously led down to bi« hotel, but on recovering he will probably tell his friends that he would undoubtedly have reached the top if it had not been for the mat de montagne, to which the most heroic cragsman must yield. The truth is that he has simply been taken sick from fatigtw. Possibly some of his companions, experienced mountaineers, when actually at the summit of the mountain, felt a very disagreeable train of symptoms which they ' had not before experienced when doing far more difficult and dangerous feats of climbing at lower altitudes. '• In short, they suffered from' the true mountain sickness, which is not characterised by sickness in its modern English signification of vomiting. The symptoms of mal de montagne can all be explained by the diminution, of osygen per uuit volume, t^oue.

True mountain eickneis cannot be recognise!'" as existing below abont; 16,500 ft. It is remarkable that very different experiences are; related by leading cragsmen. Whymper up on the Andes at 16,66dft could not get his pipe to burn, and bis guides also had to forswear the relief afforded by the Virginian weed. Yet Sir W. Oonway'e guide amoked a oigar quite comfortably on the anmmlt of Pioneer Peak, 23,000 ft above tbe eea, although he and the other climbers suffered! from distressing loss oC energy.— British Medical Journal. ' , * The longest distance that a Bhot has been fired is a few yards over 15 miles', which was the range of Krupp's well-known " monster " 130-ton steel gun, firing a shot weighing 26001b. The 111-ton Armstrong gun has an extreme range of 14 miles, firing a shot weighing 18001b, and requiring 9GOlb of powder. These guns, however, proved too expensive, being unable to stand tiring a hundred times, and their manufacture has practically been abandoned. The 22-ton Armstrong gun hurls a solid shot for » distance of 12 miles, and the discharge of the gun oannot be heard at the place whera tho ball strikes. From 12 to 13 miles is tha computed range of the most powerful guns now made, and to obtain that range an elevation of nearly 45deg is found to ha necessary. Qaiok-flriug guns are more to bs depended upon at the present day than -extreme leDgth of range, and in this respect what is considered the most wonderful of guns, perhaps, is one of the Maxims, which can fire as many &% GOO shots a minute, and yet is so light that a soldier can carry it strapped to his back.