Science and Invention.

Alexandra Herald and Central Otago Gazette, Issue 444, 20 October 1904, Page 7

Science and Invention.

THE discoloration of flowers when they are preserved and dried as botanical specimens is said to be due to ammonia in the atmosphere. In order to prevent this action, it has recently been recommended to use for pressing absorbent paper which has been baked in a one per cent, solution of oxalid acid and dried. The use of such paper enables specimens to be .preserved with their colours unimpaired.

Major Powell-Cotton's recent expedition to East Africa has proved of much scientific value in connection with some of the larger mammals of the Protectorate. The three fine specimens of giraffe which have been presented to the Natural History Museum, and are now on exhibition at South Kensington, have proved the existence of two new species.

It is reported from Bordeax that an inventor has submitted to the authorities details of a new process for paving streets with steel. The metal is formed into .blocks, which are scored to prevent horses from slipping and motor-cars and cycles from skidding. The cost of these blocks is 8s a square yard.

In Sweden, according" to recent reports, peat fuel is being used in locomotives. On the Government railway from Elmhut to Malnio specially constructed freight locomotives have been fired during the past year wholly with peat fuel, or with a mixture of the peat blocks with English coal, and the engineer's reports claim for the experiment both a mechanical and economic success. i

The St. Petersburg Physico-Chemical Society contemplates a new Arctic expedition for the following objects: - Observations of Solar radiation and atmosphere refraction, of cloud movements, and of atmospheric electricity in connection with the extinction of ultra-violet light; determination of the phenomena of terrestrial magnetism and of electric currents in the ocean ; chemical analyses of the composition of the air and water; and examinations of the Polar ice. HYPNOTIC CLAIJWOYANCE. An interesting exhibition of hypnotic clairvoyance, which later on is to be repeated in public at the London Hippodrome, was presented experimentally to a party of guests at the Hotel Cecil, the performer being a lady who, having been blindfolded and thrown into a hypnotic condition, was able to render accurately upon the pianoforte any piece of music which was placed before her, even though she had until then been entirely ignorant of its existence. A test was applied by Mr Edward German, who had brought with him the manuscript of a few bars of music which he had written for the purpose. : These the hypnotised and blindfolded ' Mile. Nydia' rendered without hesitation, and, by the composer's own admission/ with perfect accuracy. This achievement was afterwards capped by her performance of an air, the name only of which was written down by one of the guests and deposited in a sealed envelope which was placed upon her head.

CLOUD AND JVUST. A lecture was delivered at the Royal Institution recently by Mr C. T. E. Wilson, of the Cavendish Laboratory, Cambridge. Dealing with the.subject of nuclei in condensation, Mr Wilson showed experimentally how cloud and mist, as ordinarily met with, required in the first place the presence of dust in the atmosphere. Given this condition and a saturation of water vapour, any slight decrease in the pressure was sufficient to cause condensation, with formation of the minute drops of water that formed the basis of all fogs. So much had been, known, and could be easily brought about experimentally, for many years past. But it was now evident that nuclei other than dust were forthcoming. If the pressure of moist air were reduced with the latter under the influence of X-rays, condensation took place in precisely the same way, while a similar effort was produced equally well if radium were substituted. The nuclei in this case were the ions set free by the action of the radiation. The .belief was confirmed by an experiment which showed that the movement of the water particles corresponded entirely with that of positively and negatively charged particles, such as produced by these rays. So great was the delicacy of the appearance that the formation of mist could well be used as a means for detecting radio-activity. At the same time, there was reason to believe that any form of electrical disturbance was sufficient-to bring about condesation through the formation of charged ions in the atmosphere. FLEXIBLE STAY BOLTS. A flexible staybolt for locomotive fireboxes has been invented in America. It consists of a bushing or sleeve, a cap and a bolt with a spherical head. The sleeve is threaded on the outside with a slightly tapering thread at one end, which is screwed into the outer plate, the remaining threads being provided to engage the cap. The sleeves made with a flaring mouth on the water side, and on the inside of the outer end it is cupped out to form half-spherical opening which serves as a seat for the spherical head of the bolt. The spherical cap is released on the inside, and threaded, and when screwed on the sleeve it completes the ball socket. About ljin, extra material is allowed on the firebox end of the bolt for screwing in position. A NEW MICROBALANCE. E. Salvioni has devised and accurately examined a microbalance which consists 'of a thin thread or very thin ribbon of. glass or other material, fixed at one end of and placed in a closed case. The case also contains a number of small weights (the larger of platinum wire, the smaller of silk thread), which, with the aid of a handle, can be placed on the flexible thread or ribbon. The flexure of the thread when loaded is observed by means of an ocular micrometer, and, as verified by the author for his instrument, is proportional to'the weight which produces it. A conveniently placed spider thread servos as a sightlino for tho measurement of the displacements. A glass thread 10 contimetres long, and ono of two-tenths of a millimetre in diameter, will support by flexuro a weight of more than lot) milligrammes ; and, if provided with an optical arrangomont which magnifies 100 tiinois, will serve to weigh to ono-thouwmd of a. milligramme. To avoid tho iticonvcnicnco caused by subsequent oltVKticity, tho balitnoo is provided with a stop, which omnblof) tho flexuro to bo maintained after Unloading. Salvioni finds that tho loss of weight of musk by volatilisation in dourly cioinotistratod by this instrument. Tho loon in proportional to the time,