SCIENCE NOTES.

Otago Daily Times, Issue 13835, 23 February 1907, Page 4

SCIENCE NOTES.

— How far does the 'sunlight penetrate beneath the surface of tho sea? lias been asked often; and now the camera has answered the question. By exposing t|io most sensitive photographic plates at various depths it has been ascertained with (lofiniteness how' niue)i sunlight there in in tho water with descending [ oot. There is a, point nt wliieh no action oi light is found, and that point is 600 ft under 'the surface. Below that is absolute darkness, and the only way in which the mcst delicate plate can be affected in that black abyss is to send down an elccirio light with it.

— The formation of virgin soil from the rock is supposed to have taken thousands of years, and this may bo true when the sourco of the material lias been ledges f.nd boulders. To determine how (illicitly pulverised rock can support plant life is the object of an official experiment now in progress. If. waicr releases the potash of ground feldspar the first season, a promising new fertiliser is available, hut if a longer tiipo is necessary the application of the feldspar would not "bo profitable.

— According to the investigations of JI, Seurat among the Pacifio Islands there is a slow elevation going on there, which, by lifting the rcofs gradually above the waves, preserves them from erosion at the

top. awl enables vegetation find ccrtmii animal forms of a terrestrial character to exist there. This is cjsiito in opposition to Darwin s idea that the atolls were formed by the gradual submergence of small islands, that, the coral infects built up encircling reefs as the islands sank. M. Scurat shows that the elevation of tlio islands is a general phenomenon, but variable in amount, some islands. iike Aukewi, in the Gnmbier Archipelago. 'vising rapidly! n.nd others very slowly. Both the flora and the fauna of these islands are confined to a very few sp'ccies, although teen from a distance some of them appear very rich in vegetation.

— Many people have the strangest Mess about the hour of death. Some hold thai the largest proportion of deaths from disease oeeurs when the tibe eblis, i\;!ii!e others think that tho same is true til the early hours of the morning. There are yet other inoro or less widespread impressions 011 Ibis subject, but thoso mentioned .1; 1 - pear to be tho most popular ones. It, lias been slated that from time to lima careful observations have been made ill hospitals; which have resulted in showing ihat tho act of death takes place with fairly equal fretpicncv during the whole 24 hours of the day. All investigation was mado 6ome time ago in Paris. which showed that there iras a certain falling off ill the number of deaths between 7 and 11 o'clock in the evening, but that with this exception the proportion of deaths is about even.

— Tlio Japanese have attracted so much a-ttcntiori and admiration by their remarkable piogress in the ideas and practice of Western civilisation, as well as by their native genius in art. that tho results of an investigation of the brain weight of the Japanese people as compared with Europeans must interest everybody. For !(}■ years Piofessor Tnguchi, of Tokio University has been studying the brain of his Mlmr-countryin.jn. 110 shows that with adults the brain weight eomparos favourably with that of Europeans of similar stature and may even bo slightly superior. There is one striking difference, however, 111 the fact that tbe Japanese brain grows more slowly during infancy and in carl® youth tlian is the ease with Europeans. In Japan, as everywhere else, there is found a positive relation between brain weight and etatnrc —that is, the larger brains, generally, sneaking, go with tho larger bodies,

—.The figure is now being reduced by electricity l . An ingenious apparatus used by Parisian boaitlv doctors is said to bo able to take 61b or 71b otf below the waist' lino in a week. "Heat and pressure, applied in conjunction, are tho factors that do tho work—two marvellous nmv factors that in local reduction;) cxcecd (ho wildest dreams of the past. Why, madam." ->xclaims the; beauty doctor, "it I jiut. tins mould 011 you, laced it tight, and turned (in the electric healing apparatus, the, mould's heat and its pressure together would in less than an hour take an inch olf your dimensions. The treatment :s harmless, as it affects only tho fatty tissues under tho corset where the electricity is applied, and creates 110 functional disturbances whatever., I have smaller moulds, likewiso electrically heated, for rcducinu fat backs, double chins, thick ankles, and so 011. I am achieving wonderful ros|ilt,«.. Tho swift way I melt down my patrons in spots is amazing."

—An ingenious method for determining how lung ill", earth's surface had been in something like its prceont condition was worked out a few years ago by Professor Joiv, of Dublin. He estimated the total quantity of salt in the soil, and he also estiimted as closely as po.isiblo tho quantity of salt which was annually carried down '0 it, by the great rivcre. In this way ho was enabled to estimate how long it must, have taken for tho quantity of salt now present in the ecu in l|nvo accumulated. Tho result of his estimate was that some such period as one hundred million years would he required. It. is very difficult to find any flaw in this argument. Th result of such estimates nannot, of course, claim any great numerical precision, 'or a good deal of guessing is necessary in obtaining tho necessary data. But, still, when all allowance has been made, it seems unlikely that the period, can reasonably be stretchcrl to more t.lian,' perhaps, 150 million years unless somo fundamental flaw in the method exists which has escaped detection.

— The growth of tho average finger nail Is cocmputod to bo one-tliirty-second of an inch a. week, or a. little more than an inch and or-lialf a '.year. The finger nails urn said to grow faster in tho summer than in the winter. The nail on the middle finger grows 'faster than any of the other nails, awl that on the thumb grows slowest. It. is also :aid that tho nails on tho right hand grow faster than those on the left hand. According to the rate of growth stated, tho average time taken for each finger nail to rrrow its full length is about, four and a-half months, and at this rato a man 70 years old would have renewed his nailr IEo times. Taking tho length of each nail as half an inch, he would ha.'o grown 7ft- 9in of nail on each finger, ;.nrl on all lus fingeis and thumbs an aggregate length of 77Jft.

— While water is to essential to vegetation (hut so much is spent for irrigation, it can lieeome a most powerful destroyer of _ i lie vegetablo life. 31. Paul Combes points out that desert lands and polar 'icefields may support certain low forms of plants, hut mountain tops and oven sHrIiI; elevations exposed to frequent rains are kept quite destitute of any life. The re;nwaslied clays of Mekran, Persia, of moderate height. and considerable extent, have lemained since Alexander's time without a trace df a living tiling. 'Most of the fertilising material taken up by tho' mechanical and chemical action of water is lost in tho sea. and so great has tho waste become through the increased stirring of tho soil in plant culture that alarm is felt at, tho possible approaching barrenness of the world. The Tigris a.nd Euphrates have carried into tho Persian Gulf nil the fertility of Mesopotamia, ruining powerful empires. The Nile Valley now profits by the rich mud brought down by tho river, but in time Hie fertilising inatp.'ials must ho entirely dissolved out of tho rocks at the head waters.

— Experiments aro now being mad". Isays the St. James's Budget) in tho United States with a new device known as tho telegraphono. This instrument makes a permanent record of all messages sent over tho wires by telegraph or telephone—so it is claimed. The construction and operation of this wonderful instrument aro stated to bo as follows:—Tho sound waves act upon tho diaphragm of the transmitter attached to tho tolepbone, end are thence conveyed to a Ibin steel wire, where lliev are electrically stored. So soon as a record bus been made upon the wire, by placing tlio receiver attached to the tfllcgraphono to Ihe ear, ono f-an 'mmcdiately hoar tl.o message just as it was given. Records may be repoate.l as often as desired, hut as soon as there is no further need to keep them ihey may be wiped out by pausing a strong magnet over the wire, thus making it ready for use again. Tho records can be transferred for future reference by connecting the receiver cf the mncheine in daily use with tho transmitter of n lnnrc storage telephone. Should any mistake occur the responsibility can immediately ho located by rofcrenco to the records on ii'.e storage machine, an indicator showing en just what, portion of the wire apy particular rccord had been made. It is said that tho record gives such a, good reproduction of the despatoher's voico that it can be at once recognised, even though sevenl months niay have elapsed.