Science Siftings

New Zealand Tablet, Volume XXXIV, Issue 17, 26 April 1906, Page 29

Science Siftings

By 'Volt'

Tarred Koads. For preventing dust, the authorities of an English village last season distributed a thin layer ot not li/quid tar over the road surlace, and on this scatteied a mixture ol sand* and lime. ihe result- has been highly lavorable, the road being still drier and cleaner txian others in/ the mc~ inity. An Artificial Granite. An artificial granite reported from Freiburg, Baden, is made irom chips ot granite or marble, or bath. Mhese are made into a consistent putty with a suitabla proportion ot cement, water, coloring matter, and any other desired .ingredients, and tne mixture is shaped in molds and alikjjvved to set. The blocks are then immersed in water to acquire a certain amount of moisture. On removal, they are dried and hardened in a warni and shady placc k alter which' they are polished. Hay Fever. A single grain of pollen is found by l J rot. F. W. Dunbar, ot Hamjcurg,, to cuntuin enough toxin to cause intense irritatiion in a sensime hay-iever patient, and m the flowering time ol the grasses the air' may deposit as many, as lour miUion grains on a square metre in twenty-lo,ur hp^rs. 'lhis< statement is "made in answer to the objection that there cannot be pollen enough to account tor hay-fever. Pollantme, the antitoxin, is now prepared on a large! scale Irom the serum of horses treated with pollen toxin, and a drop in eye or nostril gjves prompt relief. Of ,505 j .patients,, about bl» per cent, were kept tree from ajttacks ol hay feves tiuring the entire season, while only/12.9 per cent, used the anti-toxin without any success. The Secret of the Karth's Interior. The earth, whose interior sti/1 remains one of the greatest ol mysteries, is .believed by Mr. Beresiord Ingram, an English ph>sicist, to embrace three concentric spheres, 'lhe solid nucleus he supposes to bfe, between 3UUU and 7UOU miles in diameter, and this is surrounded by a lu^nd substratum, outside of which is tthe crust, variously estimated at 7U to '2UUU miles in. thickness. More than two centuries ago, a similar theory, including the slow rotation of the inner solid sphere on a different axis from that of the entire globe, was held by Dr. Edmund Halley to account for the changes in the earth's magnetism. The axis of the "nucleus was thought to have been originally that of the entire globe. The earth's internal heat, it is no v pointed out, may be accounted for by the friction of the differently rotating bodies. As the entire globe is about 5i times as heavy as water, while the rocks at the surface average only about 2£, it is assumed that such heavy substances as gold and platinum should be at the centre, while mercury or molten lava may constitute the substratum. Wonders of the Body. The skin contains more than 2,000,000 openings, which are the outlets ot an e*fual num>bcr of sweat glands. The human skeleton consists of more than 200 distinct bones. An amount of blood equal to the whole quantity in the body passes through the heart once every minute. The full capacity of the lungs is about 320 cubic inches. About two-thirds of a pint of air is inhaled and exhaled at each breath in ordinary respiration. There are more than 200 separate muscles in the body, with an eqoial number of nerves and blood vessels. The weight ol the heart is from eight to twelve ounces. The average man takes s£ ft of food and drink each day, which amounts to one ton of solid and liquid nourishment annually. A man breathes eighteen times in a minute, and 3000 culjic feet of air every hour of Ms existence.