Science Siftings

New Zealand Tablet, Volume XXXIV, Issue 27, 5 July 1906, Page 29

Science Siftings

By «VoIt f

Vegetable Sponges. About ten species of vegetable sponges are now cultivated in the warmer parts of Africa and Asia especially in Algeria. The fruit is edible' before- maturity b)ut on ripening the pulp separates from thty fitaous material, which then becomes an excollent substitute for real sponge for the toilet, bath-room, and, many other purposes. The Algerian sponges are in large demand in Pans. The Yellowstone Park. Since the Francisco earthquake the aspect ot the Yellowstone National Park has greatly changed. Extinct geysers have agiain become active, and a new' one has formed. Yellowstone National Park is mostly in the State of Wyoming, and includes a small part of Montana. The surface is diversified by grand mountain scenery, beautiful lakes, geysers, hot springs, and cataracts. The mountains are ot volcanic origin. Numerous geysers occur in the -western part of the Park some of which eject intermittent jets o f hot waiter to a height of 250 ft. A New Use for Asbestos. The peculiar substance Known as asbestos, which was regarded as valueless a century ago, is n o w in demand foe many purposes. It is made into roofing felt, cement, theatre curtains, and various heatrresisting articles, and lias been recently spun into a light and fairly strong thread. Even ro^es, with or without steel cores are made from it for firemen. A new and rather surprising application is for army stockings, which have been shown to be- less irritating to the (feet of soldiers on the march than other stockings, and the War Department of Austria is considering their general adoption. The Decay of Teeth. Why the teeth of some people decay early while those of others continue sound throughout a long life is a problem that appears to have been only imperfectly solved. A E.uropean investigator, Dr. C. Risa, has lately analysed the saliva of 219 children averaging 13 years of agp, and has confirmed the idea that there is a relationship between the alkalinity of the saliva and dental caries. A highly alkaline saliva ensures good teeth. He has made many experiments to determine how an acid or slightly alkaline saliva may be made decidedly alkaline, and has proved that a diet containing much lime has a marked influence and does much to keep the teeth in perfect condition. Adulterated Foods. In the House of Representatives, Washington, Congressman J. R. Mann (Illinois), in supporting the Pure Pood Bill, exhibited various products adulterated with pepper, olive oil, and other articles. He- alleged that bottled cherries were picked green, their color removed fwith acid,-, and that they were then dyed a bfrigiht rodj with an aniline dye. A sample of the dye taken from bottle of cherries dyed a piece of cloth scarlet. In a bottle labelled ' pure honey ' the. contents were found to be entirely glfticose. The bottle contained a -dead bee so as to deceive the public. Patent medicines were shown containing opium and cocaine, and declared to be largely responsible for the alarming increase in the opium and cocaine habits. An Earthquake Map. Of the 30,000 earthquake shocks that occur each year about 60 are 'world-shaking;' giving- instrumental records at a great distance, and Prof. John Milne finds that these great earthquakes belong to 13 regions 3 being unimportant. The important centres form two great rings^ The chief of these rings, with a. radius ?1 6 £ , , d.frees»d .fs rees » embraces 7 regions— the Alaskan coast, the California coast, the West Indies, the Chilian coast the south ot New Zealand, Krakatoa, and Japan, and the other witha-radins of .50 degrees from its centre, in the Sahara Desert, includes .the earthquake region between India and Madagascar, the Azores, andr Tashkend. Prof. Sollas , has- concluded that the-earm has the shape of a pear, its ends being, the centres of these two rings, one in Africa and- on* in the -Pacific; 'IFhis- view has had remarkable confirmation, and the weakest* points of the earth's crust are where this theory would suggest. .