SCIENCE NOTES.

Otago Daily Times, Issue 14245, 20 June 1908, Page 5

SCIENCE NOTES.

— m — Tho Aero Club of France is about. to draft, a series of maps of tile air. Tlio president will suporintend the work,- and a vast number of documents liave been collected in onler to have all tlio infonna tion necessary. 'J'lie first few mapti are to show the position of telegraph wires, overhead cables, and all dangerous obstacles which might be struck by a balloon's guide rope at night. Overhead cables have been found conveying a potential current of 20.000 volte or more, and these might easily cause disaster to a balloon wliose otwpams art; not aware of its position. Jt is 10 help aeronauts to avoid such obstacles that, the maps aie being prepared. — Dr Pooh, the Austrian anthropologist, who uas spent a long time in Now tells of a remarkable variety of grass thai makes fierce- warfare upon other kinds of vegetations, so liliat practically nothing 0100 grows where it gots a. foothold. The natives call ilt alang. It has a tall, thick, and tough stalk; but its greatest peculiarity is its roots, Which spread out through every partite of earth they reach ojtd givo it a matted texture- something' like /ell. There is really jio room left for the roots of any other kind of vegetation. Fields of .alang cannot exist, in forests because the plaint, doos noL thrive in tlio shade. —M. CamiSlo Flammarion, the great astronomer, states thai from actual figures recently obtained Jio has become certain that tlio temperature of Europo has been falling. France has been suffering for a ' long 1 time from an excess of cold weather, the temperature at- Paris having been Ideg lielow the normal. Other readings show oven loss favourable results. The fall is more noticeable during the spring than during other periods of tbe year. Similar .conditions are recorded in our own country, Belgium, Spain, Italy, Austria, and Germany. In 'the middle of the' sixteenth century Macon was colehrated for its muscatel wines, whereas the muscatel grape ' at this moinont can scarcely be made to thrive tliere. Ancient chronicles mention the cultivation of the vine in northern Brittany, where even now apples are not plentiful. Languedoo no longer grows the lemon; thoro is not an orange loft in Rousillon. The Lambardy poplar, so familiar and picturesque in old French lino en-cravings, is nowhere to be found on French soil. These faots serve to illustrate the clanges wrought by tempera-tore in the great fruit-producing country of France. —Lite investigations, undertaken in a German laboratory, have mown the snail's ' mouth to be a wonderful piece of mechanism. It is fortunate for mankind (that no large wild animal is similarly constructed. It is armed with a vory formidable instrument in the shape of a remarkable saw- ' like tongue, which resembles a long, narrow ribbon, coiled in such a manner that only' a small portion of it is catfcd into use at once. Thickly distributed over tlio entire ; ■surface of tins ribbon are an immense num. • ber of excessively sharp little teeth. The quantity of these teeth is incredible—one species, for instance, has been indisputably . proved to possess as many as 30,000 of them. As the teeth wear away, the ribbon is uncoiled, and the others, which before 'were wrapped up in it, at the bock of ; the snail's mouth, eome forward to : take the place of those which ltave served thoir turn. The upper part of the mouth : consist? of a homy surface, against which ■ the sharp-tooth tongue works. So effective an instrument does this tongue prove that the tough leaves of tbe lily may often bo found to be entirely rasped off by it — One of the most remarkable outcomes of the demand for time-saving devices of ■ the .present day in facilitating oflice-work routine is the improvement of the typewriter. From a writing machine pure anil simple it has blossomed'into an all-round adjunct of the counting- house. The latest of these commercial auxiliaries is allmost human in its action. It writes upon a M surface, such as a. page of the ledger or cash-book, the writing- mechanism travelling up and down the sheet like the hand in writing, _ and will work equally well upon any size of page or paper of any thickness. As a labour-saving' device it j is probably without parallel. Ono large ' industrial firm which has adopted the ap- ; plianee has to make 16 records of an order. Formerly this required no lees than 10 • separate i operations; now the typenwitev ] does it in two. Similarly, a London bank ' uses the machine not only for posting the '. books, but adding up the -money columns ; as well; while one machine will mot only ' post up the ledger, hit prepare tho customer's statement at one and the same ; time. . . —The heights of objects can be found ' in •.ifche. following, lriasnier from the lengths of;'their shadows:'— Set a-stoke vertically • in.the ground,'and -.wait'until the length • : to • the height'' -Ait; the same time mark a ppofc • .on the ground where the shadow Halls of the top of the tree, steeple, or other object : to be measured. The length of the shadow ' is then equal to the hoight of that object. ! There are pads of the world and seasons of the year wherein this method cannot ' be used.' lu all places having a latitude ' higher than 68Jdeg. either nointih or south, ' the shadow of the object is always longer ■ than (the height. In. a similar' way the I height of a steeple or other object, may ..be ; found by proportion. Suppose that' tho ' length df the shadow of the steeple is 120 ft, ' the lcttglih of tlio staff's shadow is 6ft, while the height of the staff is 6ft. . The haiglrt of. .Mie staff is to die length of the staff's '■ shadow as the height of the steeplo is ' to the shadow of the steeple-Matt is, 5: ' 6 as x: 120, hence the height of the steeple is. 100 ft. 1 — The' fact that natural pruning occurs lias long ten known. The subject has . heen studied by Mir C. St.ua.tt Gager, who has a note on die-subject in tho "Journal ' of llhe New York "Botanic Garden!" Xatural pruning means the Joss of certain branches alter their death, usually caused by overshading, and consequent poor nutri- ' toon. In this process the tree is passive until the branch.io be removed is dead, . after which it is cut off by the formation of a "collar" of tissue by the cambium. This explains the absence of branches low down on the trunk when trees are crowded ill growth. . Such trees 'that have been pruned by environmental forces, as dc- ' scribed above, furnish timber much freer ' from knots than that obtained from trees that have grown in the open, where tho ' lower tiranohfs have persisted. Natural ' pruning does not appear to benefit a plant \ to any extent. A second method, termed self-pruning, is described, which is distinguished from natural pruning in that ■ the tree is an aor-ive agent in the- process throughout. In this instance the branch ' dies as a result of tho pruning, whereas in natural pruning the branch is pruned after it is dead. In some trees self-pruning is J by the formation of an abscission layer similar to that formed 'at the base of leaf-stalks, and thus the branch is cut. off from the tree. In other trees, as willows, 'instead of tho abscission layer, a brittle zone is formed at the base of the branch. During the month of October,the sapling poplars (Populus deltoides) in the New York Botanic Garden were vigorously, pruning themselves, the ground being littered with branelios, most of which axe two years old, some older, some yoimgor. These pruned branches bear well-formed winter buds.— Knowledge. —M. Banbieri, of Paw's, recently carefully analysed the yolks of hens' eggs, and separated a certain number of compounds. The first body is the oil of the yolk, and when this is purified by animal charcoal, it is found to be quite free from nitrogen, phosphorus, sulphur, or ash. Analysis of the oil shows it to be mado ,up of carbon 76.5, hydrogen 11.7, oxygen 11.8 parts. Its composition is therefore very near that of trioleine. The second compound is a solid substance, w-hich is soluble in hot alcohol, but upon cooling it is separated in the form of a jelly-liko mass. After purifying, it yields a white crystalline body, which melts at about 140deg- Fahr. Its composition' is carbon 76.2, hydrogen 12.2, oxygen 11.6. This body is identified with ,tristearine, and <tihe latter has the same molt,in<f power. From the two bodies can lie separated stearic acid, oleine, and stearine. Another body found in minute quantity is a while crystalline substance. It it sulublo in an excess of alcohol, and tho solution is neutral. It melts at 356deg Fahr., having the composition: Carbon 64.8, hydrogen 11.3, nitrogen 3.66, phosphorus 1.35, sulphur 0.40, oxygen 18.49, ash 0. This body, mixed with tri-stcarino, wais observed by other experimenters, and known as ccrebrine. By its composition it seems to l>e related to the cerebrio acid of Fremy. M. Barbieri proposes to call it ovine. He also obtains a white mass from, tho yolk which divides into two layers—a. lower oily jiortion and an upper' layer. Treating the lail-ter, he finds a substance which swells up when placed in woodspirit, but. did not continue to obs'srvo ' it at present. From the yolk he then separated a body known as ovo-eholestorine. When purified it appears as a crystalline comppimd, and has the composition: Carbon 83.44, hydrogen 11.84, oxygen 4.72. Another body .is an oil which has an intense yellow colour, known as. chroma-tine. When treated by ether or chloroform it yields small octahedral crystals, whose - melting point is found to be 239deg Fahr. I i What is remarkable, is that these crystals J at£ searly pure sulphur. ~ j