SCIENCE NOTES.

Otago Daily Times, Issue 14441, 6 February 1909, Page 10

SCIENCE NOTES.

— Tlio furnace as a. means of ventilation is said to lie more economical in deep mines Mian in shallow ones, as it acts by heating a column of air; the higher the column the greater will bo the difference in tlio weight of air in ihe upcast and downcast shafts, and consequently the greater the motive power. — Experiments have recently been mado in Herlin to ascertain the height at which a balloon may be considered immune from hostile rifle shots. Captive balloons were sent, up, and they wore shot at from angles of from 15 to 45 degrees. Balloons travelling at a height of from 600 to 2000 yards could bo hit only once out of six shots, while they were perfectly safe at a height of 3000 yards. Kvcu when .struck the damage to the gasbag was so small that tlio balloon was able to continue its journey for hours before the escaping gas made a landing necessary. Ihero is liitle doubt that the Irish-

man, with the classic features ami tho speculative eye, despite the .Milesians or tho 'luatha do Danaans, is of u kindred woe with Iho Greek. Whore (asks Popular Science Sittings) shall lxj found the gonuino Knghshnian—the Stixon? Iu a population of 40 millions of so-called Englishmen there arc perhaps 15 per cent, who can go hack to 'Witonagemot, or genuine Angio-Saxon days. The. Scottish race are of Indoburopean origin, as Celtic as their greatest strain, the Northern French, while tti** people of Eastern Franco are (iauls of a strong -Germanic type. — A Belgian has designed a now typo of aeroplane. This inventor has selected as his model those insects which belong to tho locust or criclcot variety, and lie has therefore named his machine the "Orthoptone,' because ho hopes that it will reproduce exactly tho mode of flight adopted In* tlic insects belonging to tJie orthoptera. class. Jhe wings will have an area, of six square yards, and motive power will bo obtained through a 100 h.p. motor, weighing only about 2201b. Tiie weight of tho whole contrivance will not exceed 6701b. —It is well known that the poisonous principles called ptomaines are generated \ory rapidly and readily in foods which, perfectly sound so long as they remain hermetically sealed from the ai-ir in tins, liecomo hurtful when the contents of tho tins are exposed to the air. This is specially the caso when the exposure takes place in close, stuffy, and confined places. Sti'l more likely is it that poisonous properties Will be produood when the foods are loft open in places adjacent to sinks and drains, or in sleeping places, where, as in the caso of flic poor, the ventilation is far from adequate. The rule regarding tinned foods should be to consume them as quickly as possible after they have been opened, and we would add that tho layers of meat which have boon in contact with the tin should not ho consumed at all.

i ~ A rc ' n,cd y for dry-rot is pctroleum. iho affeetod parts of the weed arc painted with it, which ranges t.lie fungi lo die, turn black, and finally drop off, Tho best preventive of dry-rot is plenty of draught. If iho portions are already affected 1 60 badly that they have to l>e torn out- and renewed, the newly-inserted WO od is coated with "carbolineum" to prevent <i fresh appearnnec of drv-rot. Another remedy is ordinury suit, "it absorbs the moisture of the wood, whereby it is itscif dissolved, thus gradually impregnating tlio planks, etc.: In order io combat dry-rot with sa.it, ilirow salt into boiling water until iv'm su,um ' e< ' solution is obtained. " ,tll ""s repeatedly wash tlio wood and masonry afflicted with dry-rot. Wherever IH-aoticable the salt may be sprinkled dircot upon the affected place. — A common error with regard to tho chameleon is that it can assumo the colour ot any object upon which it may happen to be : plnMd. The fact is the' animal's capabilities m this respect arc limited to a lew shades and aro duo to the effusion of secreted pigments in tlio skin. No matter where or when a chameleon mav tx- observed, it is invariably mottled. Tho external parts of its body differ widely fiom any other class of the rcptilia. The revolving eyes, prehensile tail, double *eet, and the <|iip«r projection of tho skull boStow upon It ail alwurd though wonderful' appearance. Such powers, however, as lielong to tins droll crealure must necessarily command rospect. An unsuspecting fly •ilijj lis before those weird-looking optics, » huge mouth gapes, a long elastic fleshy substance darts forth witli lightning rapidity, and the chameleon's countcnanco assumes an aspect of gravity and Mreiiitv Iwrn of satisfaction. The fly has disappeared.

— there is a warning io smokers in a rcccnt. issue of the UritMi .Medical Journal from l'lofis-or .1. Dixon Mann, of Manchester. lor 30 years or move it has been nolievcd that pra-elicallv no nicotine piiKSea over with i||o smoke of tobacco, and that Uiciofoie nouii can he absorbed hv tho sinoker. Oth<»r constituents of the smoke, especially pyridine, were blamed for such injurious efforts as smoking wa<s known to produce. Later and more ox act chemical research has shown that the experimental evidenra (nearly 40 yeur« ol<l| oil which I hoc beliefs rosiod was incorrect. llceent experiments have proved that from onetwelfth io two-ihirds of the nicotine in various kinds of cigars jiassps over in Iho smoke as pure nicotine. The importance of this discovery is that nicotine is undoubtedly an energetic poison. The chemical experiments have been confirmed by experiments on animals and by observations of tlie effect, or rather absence of effect, on healthy non-smokers of smoking nicotinefree tobacco.

— Far up in tho mountains of Ceylon there is a spider that spins a weh'like bright yellowish silk, (he central net of which is sfi in diameter, while the supportmg lines or guys, as they arc Killed, measure sometimes 10ft or 12ft. The spider seldom hues or stings, but should anyone try to catch him he will bile, and, thoueh not venomous. h, s jtfws are as powerful »=. .i beak. Ihe todies of .th CS o Mikk-is are very handsomely decorated, being Inight gold 0 r scarlet underneath while fha upper part is covered with the moM <iclicuto slate-coloured fur. .So stromr are the welw that birds the size of larks are frequent y caught therein, and oven Ihe small but powerful scalp lizard falls a and wale!led the "yellow monster-meLsw »IS iS't ;1S; «;•«" 2 5" £ Xl'V-i*" dark nooks of"L • '"f" 7 " nfrw l»entcd