POPULAR SCIENCE.

Gisborne Times, Volume XXX, Issue 3431, 24 January 1912, Page 8

POPULAR SCIENCE.

SUSPENSION OF FISH LIFE

Interesting experiments on the possibility of suspending life for a definite period are being carried out by Professor Raoul Pictet, at Geneva. In one case he froze live goldfish in }ce to a temperature of 9 deg, Fah. below zero, and three months later gradually melted the ice and brought the fish back t*> their natural live state. He also kept a dog frozen for an hour at a temperature of 110 deg. below the freezing point without its dying. WHEN WASHING LINEN.

In the ordinary process of washing, the linen is subjected to a rather severe j rubbing treatment, w'hich is not oalcu- j lated to prolong the life of the mater- j ial. An invention calculated to obviate j this disadavantage consists of two ribbed rubber rollers suspended in a frame which is provided with a handle for convenient manipulation. The action hardly requires explanation. The J linen, soaked in soap suds, is laid upon j an inclined board, and the instrument j is then passed to and fro over the ar- j tide like a brush. While this opera- j tion thoroughly works the soap suds \ into the material, and assists them in their detergent action, it is free from the defects inherent in the action of a brush. ATTRACTION OF MERCURY. There are no metals w'hich are attracted by mercury, or quicksilver, as it is; ' often* called, as iron is attracted by a j magnet. Mercury will wet and adhere , to a largo number of metals when they ! are clean, just as water will wet clean | glass ? and it will dissolve thesemetals, j forming amalgams with them. Tin, gold, ] silver, lead and copper are the more ! common metals to bo thus attacked by ; mercury. PROTECTION OF IRON PIPING. After a number of experiments to protect its service pipes against electrolysis, a St. Louis gas company is now covering its wrought iron piping with layers of pitch and paper. This method seems to be proving successful. The wrought iron pipe is first coated with tar and pitch mixture, heated and thinned sufficiently to flow easily, and on to this a 4in paper ribbon is wrapped spirally, its edges overlapping. This paper covering is then tar-painted, and again wrapped with paper, the process being repeated until four successive coats of tar and paper have been applied. Pieces of pipe thus insulated have been placed in the ground under conditions distinctly favorable to electrolysis, together with other lengths not so treated, and after being taken up at the end of two years, the unprotected pipes were badly pitted and almost completely destroyed, while the insulated piping w r as practically in the same condition as w'hen laid. It is believed that pipes so treated will have their life at least doubled. Only wrought iron mains being less subject to corrosion and electrolysis than the former. THE STRENGTH OF GLASS.

Glass is a substance that we cannot figure the strength of as we can a great many other things with w'hich we are familiar. It varies greatly in itself. The strongest glass as a rule breaks into the greatest number of fragments. Comparing the strength of thin glass with thick, the former is relatively the stronger; this is a thing very often lost sight of. Then, again, as to the difference between rough plate and polished plate, wo find polished plate the stronger. This is perhaps to be attributed to the fact that all the. very fine surface hair cracks are polished off. These only go into the glass t-o a certain depth, and when they are all or nearly all polished and ground off, there is less chance for some of them to form the basis of a crack, and thereby the glass is increased in strength. Tests have been made, and some formulae have been arrived at. As was to be expected, they show' very irregular results as to the strength of glass.

FOR ROWING PRACTICE. The young oarsman is apt to experience difficulty in keeping a straight course until he has had some practice. Rowing a boat without a steersman in a narrow channel calls for considerable skill to hold a course in mid-stream. A variation of force in pulling the oars almost instantly results in the boat making a landfall on one or the other of the banks. The skilled oarsman does not need an appliance that the beginner might welcome. With the aid of a mirror conveniently, supported at a suitable angle and height before the oarsman’s face, the water, the shores, and approaching boats may be seen with distinctness. The mirror may be set directly in front or a little distance to one side A POISON OF SLEEP.

Considerable discussion .has arisen in scientific circles over the experiments of MM. Legendre and Pieron in Paris, who have discovered that the real reason why we go to sleep is because our brain has been actually poisbned. Sleep, they declare, is produced through a morbid change in the cells of the frontal lobe of the brain. They discovered a dog that died of insomnia, and injected some of the serum of its brain into another dog, thereby causing it to fall into a deep sleep, from -which it subsequently awakened in a perfectly healthy condition. From this and similar experiments they assert that sleep is due to a natural poison. The poison of sleep, they contend, is in fact, an antidote for the poisons that are the by-products of every mental and physical action of our lives, and we awake from sleep when it has cleansed our higher nervous centres of the poisons that our daily toil has produced. These experiments should lead to the discovery of a practical sleep inducer.