SCIENCE NOTES.

Otago Witness, Issue 2862, 20 January 1909, Page 84

SCIENCE NOTES.

— Professor J. A. Thomson, of Edinburgh, announces the discovery in the Faroes of a large specie^ of antipatharian coral, a group previously unknown to be represented in British waters. The specimen, which stands abouc a, yard in he'ght, was dredged up by a. fisherman, and has now found a home in the University Museum at Edinburgh. — The drcdgings recently made in the English Channel ha\e resulted in a discovery of ohalk under the sea south of the Fddystone Rodk. Th-o dredgings constantly brought up flints from the mid-Channel beds, ajid it is by means of the westerlytidal wave that these are the source of a never-failing supply of gra,\ c] on England's southern ' coasts. • —It is a common experience with deaf people that, quite irrespective of intensity, they can hear sounds of a certain tone much better than others, and the particular timbr.© varies according to the subject. It may not be beyord the reach of science to devise what might be termed ear spectacles, the function of which would be to modify the timbre of sounds on their way to the ear in such wise as to confer upon them the special quality that i 6 indispensable to hearing in ears that are acoustically defective. i — Everyone acquainted with Greek mythology remembsrs bow Theseus, the benefactor of prehistoric Greece, went over into Crete, and with the aid of Ariadne and a bail of twine threaded his way into a labjrinth built for King Minos and killed the Minotaur, a portion of whoso food consisted of Athenian maidens. Discoveries just made in Crete (says Popular Science Siftinga) have «-erved more than to sug"gest that the stories have an historical foundation. Xot only the capital of Minos, but his palace, his throne, and now a labyrinth which may well have been devised by "a leal Daedalus have been discovered in the ruins' of Knossos, in the- centre of the island. —Aa experiment, brutal, but bordering close to the wonderful, has been made in the olay-testing department of a machinery company at Bucyrus, Ohio, U.S.A., in which a toad was placed in a 20-ton brick press, and was four times subjected to a pressure of 11,0001b, without injury. The question at issue was whether such a pressure, would kill the toad or whether its ability to compress itself was suffioient to allow it to come out of the ordeal alive. Th© toad was first placed in a lump of granulous clay, and the whole pressed into a brick. After the huge press had dono its work the solid briok was lifted from th© machine, and the toad winked its eyes contentedly, stretched its legs, and hopped away. j j — Professor Schleich, of the Yirchow Hos- : pital, Berlin. ha« discovered a new anaesthetic (producing lr-ensibihty). It consists | of two parts of oihyl-chlonde, four paTts of chloroform, hnd 12 parts of sulphuric ether. This mixture boils at a very low temperature— in fact, at the normal temperature of the human body. If anyone clasps a phial containing it in his fist for a few minutes it boils gently. The patient inhales the vapour of the boiling liquid, j and quickly it produces freedom from pain, j then sleep. If the phial be held under j his nostrils so that he continues to inhale | the vapour his sensory nerves are blunted, j end he becomes ansesthetised. Professor ' Schleich insists that there is no danger in ' using the mixture. He has employed it in } more than 15,000 cases both in private and ; hospital practice. He has used it as a, 6edative in nervous disease and in affec- \ tions of the heart, and as a narcotic to ! ease the excruciating pains whioh characterise some diseases of the internal organs. 1 Its simplicity and harmlessness recommend i its us© in war, says Professor Sohleich. j He sug^oste that each soldier could be i provided easily with a small quantity of j the liquid in a suitable tube, which he could use for himself until he found himself in the surgeon's hands. It would be impossible for a soldier to administer an overdose to himself. Me would fall asleep first. | — One of the sights of the Great Salt ! Lake of Utah, developed by the progress of 'Oientific industry, ie the system of. immense salt-making ponds on the shore of the lake. At Saltair the lake water is pimped into a great settling basin, where the impurities, fall to the bottom, and, containing much iron, form a reddish deposit. From this basin the water i 6 drawn off into "harvesting ponds," averaging 90,000 square yards in area, and 6in in depth. The ponds are kept supplied with water. a« the evaporation goes on. from May to September, when the 6alt harvest begins. The water ha\ ing disappeared a dazzling layer of salt, 2in or 3in thick, is found covering the bottom of the ponds, which is broken up with ploughs before beins conveyed 1o the mills, where the final crushing and winnowing- arc done. In general the salt marshes of thf Congo region represent a kind of pocket or rift in the soil. They arc to be found in eon-idi?r-abl" numbers in the district of Sambait, and there are also many of thepe marshes on the left bank of the River Lufu'm. The walls of the rift show first a layer ' of blackish clay mixed with Rand and oon- j taining numerous quartz and silex pebblos or more exceptionally black and white shells, fragments of oyster and mussel. Then j comes a layer of stratified and grey-blue ] schist. The soil of the depression also contains schist as the greater constituent, and is covered by a layer of sandy cay. i In order to collect tl;*> salt the nafhfs dig a. tunnel-shaped hole from 6ft to "*Cf t in diameter ami about 3ft deep. The cavity soon fills up with a warm and clear Water, which is «troi>gly charged with rait. It comes up w ith considerable pressure, and the liquid se-pnics to boil. The pa!t i« partly precipitated at the bottom of the cavity, and mixes with the soil to form a blaokjsh mud. The latter is washed out with hot water to extract the salt, which is then orystallisnd from the solution. The product which is thus obtained is of a salty grPv colour, and its taste is more I alika!i;io tTian thar of Kuropean salt. THE SCARCER METALS. The absorption of th-p v.oiltl's natural t=< uirr's by tlir* f<-\v at the expense of ii' ii .ni\. <a->e!iu- to ha\o cone further with I ' ■i! io ih-? =urfer motals than in any < 1 "i- direction At the present time the i-uuph of prarticaliy all of theso if absolufe]v controlled by a single concern in London. Take bismuth, for example. It is an indu~tnal necessary. But if you want to

buy any you must go, directlj or indirectly, to this English firm, which owns all of the important deposits. Of such deposits tho principal are in Bolivia. The London concern is also proprietor of rich bismuth, mines in Peru, but it does not allow them to be worked, Jest eua. oversupply tend to reduce the price. For many years the- price of bismuth in the market has been LTodol a pound wholesale. In Bolivia, which yields the bulk of the supply* it occurs in the form of sulphides and carbonates. A few tons a year are produced in the United States, but they go to the London firm. Great quantities of the metal are used, in the form of cubnitrate and other salts, for .making the more expensive kinds of toilet and baby powders ; but it becomes a necessary in the manufacture of type, being introduced as an ingredient to cause the type-metal to expand in the moulds and to fill them perfectly. Thus the finished letters have sharp outlines. Within the last few years ceijt-ain interesting metals, all of them rare and costly, which in Nature are associated with platinum, have found important industrial uses. The supply of these is controlled by the same London firm. One of them is rhodium, of which crucibles are now being made fcr uee in chemical laboratories. For such purposes ihe material is admirably adapted, inasmuch as it resists the action of many chemicals against which platinum is not proof. Even aqua regia, which will dissolve both gold and platinum, has no effect upon rhodium. One can boil lead in a vessel of this steel-grey metal. But the same thing cannot be done in a vessel of platinum, for the latrer will mix with lead a 6 readily as sugai does with water, notwithstanding the fact that lead melts at 850deg Fahrenheit, while the melting point of platinum is 3325deg. An incidental advantage of the rhedium crucible is that it will not blister, as one of platinum is liable to, if exposed to 2. Bunaen burner. Another metal of this same group is palladium, which possesses one very extraordinary property. It eagerly absorbs hydrogen, taking up six hundred and fifty limes its own bulk of the latter. In & state it will absorb one thousand times its own volume of hydrogen. Though, the metal itself is silvery-white the powder is black. Palladium — which, -by the way, approaches steel in hardness — is employed in the making of exactly-divided scalee for delicate scientific instruments and also in the manufacture of watches and chronometers. The price of it. as with the others of the same group, is variable and indeterminate. If you want a few ounces o* any or these metals you can get them only by applying to the London firm, directly or indirectly, and you will have to pay whatever they choose to task. Yet another of these metals ; .a osmium, which is equally remankable in it 6 way. In the first place it is the heaviest of all known metals^ — more than one-sixth heavier than gold. Secondly, it will resist a higher temperature than any other metal, its melting point being 4532deg Fahrenheit. The only industrial use thus far found for it is as a material for filaments of incandescent lamps. The osmiuni filament has more efficiency than the carbon filament, yielding more light for a given current. But it has the disadvantage of being expensive and brittle. There remain of the same group ruthenium and iridium. It has been suggested that the former might be used advantageously for crucibles, inasmuch as it is very resistant to chemicals. As yet, however*, it is hardly more than a. curiosity of the laboratory. This was said of most of its Bister metals only a few years ago. As for iridium every gold pen is tipped with an alloy of it to lend durability, else the writing instrument would soon wear out. It is one of the hardest ef metale, lustrous white in colour, and the heaviest of all the metals, excepting only osmium. In this last respect the difference between the two is trifling. Knife-edges for delicate balances are made of an alloy of iridium. When one wishes to express the idea of great weight one says tliat a thing is "heavy as lead." In the popular mind lead is a sort of standard of extreme heaviness. Yet, as a matter of fact, osmium and iridium arc about twice as heavy as lead. Even gold, which is considerably lighter than either of the^e. Ie more than" nineteen times as heavy a 6 water, while lead is only a little over oleven times as heavy as water. Palladium, rhodium, and ruthenium are comparatively light, being only a little heavier than lead. Now all of these rare metals of the socalled platinum group are obtained merely as by-products in the refining of platinum. Thus it comes about that the London concern which controls the world's supply of pktinum aleo holds in its exclusive hands the entire available supply of rhodium, osmium, palladium, iridium, and ruthenium.