Science Siftings

New Zealand Tablet, Volume XXXVII, Issue 19, 13 May 1909, Page 755

Science Siftings

BY • VOLT

A Dangerous Cargo. Lime is one of the most dangerous of all cargoes for a vessel to carry. When it catches fire, as it frequently does, in spite of the greatest precautions against the admission of water into the hold, it is almost impossible to extinguish it. The only method that ever avails is to stop every crack with soap, so that no air can reach the lime. Sometimes this will stop the fire, but often these fires will burn for weeks, till the vessel sinks beneath the water, a mass oi" charred embers holding together. Do Plants Breathe? Respiration is a part of the life of all organisms, animal and, vegetable. It is a series of chemical changes, the first of which is the absorption of oxygen into,, the body and the last of which is the exhalation of carbonic acid. Any organ adapted to this double work — the inhalation of oxygen and the exhalation of carbonic acid — is a lung, though of course the organ is much more rudimentary in the plant than in man. ,It is none the less true, however, that every living organism, whether plant or animal, breathes. No Imitation Opal. It is said that all the precious stones have been counterfeited, with more or less success, except the opal. That stone never has been and perhaps never will be counterfeited, for the reason that it is made up of innumerable facets so held together by cohesion as to refract the light like a prism. It is this quality that produces the well known iridescent effect. A few artificial opals have been obtained in the laboratory, but they seem to have been accidental, as repetitions of the experiment have not succeeded. Ancient Locks. Locks were used in the time of the Pharaohs. At Karnak the visitor is shown the sculptured representation of a lock which is almost exactly like the kind of lock used in Egypt at the present day. Homer says that Penelope used a brass key to open her wardrobe. He adds that it was very crooked and had an ivory handle. A Greek writer who lived in the last half of the twelfth century explains that such keys were undoubtedly very ancient, although still to be seen in Constantinople and elsewhere. Roman locks, like the Egyptian, required a partial sliding of the key. They were, however more intricate. The Test of Hardness. A good many people appear to think that resistance to a blow is a test of hardness in minerals, whereas it is resistance to erosion. ■ Ignorance of this fact led a man not long ago to experiment on what appeared to be a large and unusually clear garnet of rather light red color. He took a hammer to it and smashed it to atoms. A diamond is the hardest substance in the world, yet it may be broken by a tap from a hammer or even a fall on the sidewalk, as it is apt to split along any of the cleavage lines, which are parallel to its faces. Experts test an undetermined gem first with a file and after with a fragment of stone of differing hardness. If it yields to the file, it is a glass or something no more durable than that. Waterproofing Matches. Perhaps some or your readers would be interested to know that I have found a simple, inexpensive way to waterproof matches (says a writer in the Scientific American). Into some melted paraffin (care being taken that it was as cool as possible) I dipped a few ordinary parlor matches. After withdrawing them and allowing them to cool it was found that they scratched almost as easily as before being coated with the wax. Several were held x under water for six or seven hours and all of them lighted as easily as before immersion. When the match is scratched the paraffin is first rubbed and the match lights in the usual way.. Matches treated as above would be very useful on camping or canoeing trips, as they do' not absorb moisture. Since more rubbing is required to light them than the ordinary match, it would be practically impossible to set them on fire by accidental dropping.

You can lose your situation, You can lose your rank or station, You can lose your reputation, • You can even lose your wife ! But if this advice you follow When your cough sounds harsh and hollow, And Wooßs' Peppermint you swallow, Ypu will never lose your life.