Science Siftings
By •Volt*
Magnetism in Motion.
For twenty-five years the nature ,of magnetism, a problem scarcely less bewildering than life itself, has been a siubject of research by Joajjn.es Zacharias, the German engineer-. He has experimented patiently and in many ways with magnetised and unmagnelised materials, with ordinary and special magnets, and has concluded that this singular force is not a stable state ot matter, but— like light and heat— is a motion of molecules. This he holds 1 to 'be true ii& the case of permanent magnets as well as electro-magnets. Some of his results are quite magical— as the rotating of a suspended steel ball enclosed in a glass tube by turning a copper ball on the other side of a partition, or aisplacing metallic balls by the heat of a lighted cigar or even' of a finger, or causing horseshoe magnets to rotate non-magnetic discs like selenium or magnesium..
Red Light and Fevers
Red light was shown by Finsen, the Danish physician, ,to have a decided influence in fevers of certain kinds, especially in lessening suppuration and other symptoms in smallpox. Carrying the experiments further, Dr. Goldman,, of Vienna, recently vaccinated a number of children in two groups, keeping one group in red light with red bands over the wounds, atnd the other group under the usual comditions. The results have been surprising. The children exposed to daylight had the usual swelling, inflammation, suppuration, etc., but in the others there was no development of pustules or inflammation. Dr. Goldman believes there was no lessening of the preventive power of the vaocination.
The Flavor of Eggs.
The flavor of hens' eggs is declared by an English medical man to be very materially affected by food. When the hens act as scavengers their eggs are made unfit to eat, but a diet of sunflower seeds produces remarkably fine an(d sweet eggs.
Composition of Coal.
Analyses of 350 samples of coal from 44 French Belgian, German, and British mines have shown that a good coal should contain about 20 per cent, of volatile matter and not more than 6 to 8 per cent, of ash.
Longevity in Animals.
Some interesting statistics have recently been published as to the relative age of the various domestic or domestioated animals. Among the larger species there is some uniformity. For the horse and the ass the extreme limit is 35 years, and for the horned cattle about 30. For the dog it is given at 25, while sheep, goats, pigs, and cats are grouped at 15. But there are stranger disparities among the birds. 'While a goose may live 30 years and a s<parrow 25, a crow as many as 100, ducks, poultry, and turkeys die of old age at 12. The palm for longevity is divided between the elephant and the parrot, for both pass the century.
Hard and Soft Woods
Some interesting experiments have been made to ascertain which wood lasts the longest. It was found that the bircfli and aspen decayed in three years, willow and chestnut in four years, maple and red beech in filve years-, and elm and ash in seven years. Oak, Scottish fir, and Weyraouth pine decayed to the depth of half an inch in seven years ; larch and juniper were uninjured at the end of seven years. In situations so free from moisture that they may be practically called dry, the durability of timber is unlimited. The roof of Westminster Hall is more than fo.ur hundred and fifty years old.
Permanent link to this item
Hononga pūmau ki tēnei tūemi
https://paperspast.natlib.govt.nz/periodicals/NZT19050727.2.20
Bibliographic details
Ngā taipitopito pukapuka
New Zealand Tablet, Volume XXXIII, Issue 30, 27 July 1905, Page 6
Word count
Tapeke kupu
585Science Siftings New Zealand Tablet, Volume XXXIII, Issue 30, 27 July 1905, Page 6
Using this item
Te whakamahi i tēnei tūemi
See our copyright guide for information on how you may use this title.