Scientific and Useful.

Western Star, Issue 944, 2 May 1885, Page 1 (Supplement)

Scientific and Useful.

EAT SLOWLY. The Lancet, commenting on the advice to hunting men to reduce their weight, says, “ 110 not try it.” No meaeure will suffice which is not injurious. “ If we only ate more deliberately we should find half our accustomed quantity of food sufficient to satisfy the most eager cravings of hunger.” “ Let men of all classes who lead healthy active lives, resolve to eat and drink slowly.” LAEGE FEINT FOE CHILDREN. Mr Brudenell Carter urges all parents to test the vision of their children as soon as the latter know their alphabet. Ho urges upon all who have control of schools, the examination of new pupils and the allotment of tasks in accordance with their capabilities of vision. All lesson books for very young children should be printed in large type, and the children compelled to keep the books at a distance when reading thorn. Many of the school books now in use should be abandoned, and others prepared of at least twice the size and legibility. PATENTS.

The number of patents applied for during the year 1884, under the Act which came into force on the first January of that year, was 17,110. The largest number reached in any previous year wrs 6241 in 1882. In 1883 the number slightly fell off, doubtless in consequence of many patentees preferring to wait for the reduction in fees effected by the new Act, though the number of 5993 was reached —a number in excess ol the year 1881 (5751), and of any previous year. It may be added that no approach has yet been made to the average number of applications in America. The number of patents applied for in the States in 1883 was 33,073.

COBK BEIGES. The Annales Industrielles describes cork bricks, which it says are now being employed for various purposes, such as for coating steam-boilers and ice-cellars, and for many other purposes. They are thus made: —The cork is freed from woody particles and other impurities by a winnowing process j the wind from the ventilator throws the cork into a second machine, where it is cut to pieces, a-’d is thence drawn up into buckets and ejected into a mill, where it is ground to a 1 impalpable powder, which is then kneade 1 up with a suitable cement and pressed into bricks. The cork bricks are first dried in the air, and afterwards by means of artificial heat. They are hard and not liable to decomposition, and keep off moisture, heat, cold, and sound. “ PEOTECTIVE RESEMBLANCE." In Mr Johnston’s account of the ascent of Mount Kilimanjaro, in Equatorial Africa, the following passage occurs : —“ Other noticeable features in the scene were the (all red ant hills,, and, strange imitation, the (all red antelopes, a species of hartebeest, resembling faintly in shape the form of a giraffe with sloping hindquarters, high shoulders and long neck. Being a deep red brown in colour, and standing one by one stock-still at the approach of the caravan, they deceived even the sharp eyes of my men, and again and again a hartebeest would start up at 20 yards distance and gallop off, while I was patiently stalking and ant-h'll, and crawling on my stomach through thorns and aloes, only to find the supposed antelope an irregular mass of red clay.” ANTHROPOLOGICAL. The current number of the Journal of the Anthropological Institute contains a paper, in which Mr Francis Galton gives an account of the work done by the Anthropological laboratory, which he organised at the" Healtheries.” Ho has tabulated the records in an ingenious way, and obtained some remarkable and interesting results. For instance, he finds that the brea'hing capacity of the men tested at the laboratory was vastly greater than that of the women 5 that the mean height was sft. Sin. and sft. 3in. respectively; that the strength of pull was nearly double in men; but in keenness of sight the women were very ’.nearly eq-al. The span of the arms is in the proportionable human being equal approximately to the height, and Mr Galton finds it so in the case of women ; but some long-armed men visited the laboratory, and the average length of span comes out 2in. greater th m the average height in the case of the men.

rrnmOATioN or watze by motion. A discovery has been made by Dr Pehl, of St Petersburg, which promises, says the Colliery Guardian, to have a very important bearing on many industrial processes. The water of the riaer Neva is very free from bacteria, having only about 300 germs iu a cubic centimeter. The canals of St Petersburg, on the contrary, are infested with bacteria—their number reaching 110,000 in a cubic centimeter, even during good weather. The same is true with regard to conduits of water for supply of the city. While the chemical composition of the water passing through these city conduits hardly differs from that of the Neva (by which they are supplied), the number of bacteria reaches 70,000 against 300 in the water taken from the river j and the worst water was found in the chief conduit, although all details of its construction are the same as in the secondary conduits. Dr Pehl explains this anomaly by the rapidity of the motion of the water, and he has made direct experiments in order to ascertain thnt. In fact, when water was brought into rapid motion for an hour by moans of a centrifugal machine the number of developing germs was reduced by 90 per cent, Further experiments will show if this destruction of germs is due to the motion of the mass of water or to molecular motion. If this discovery of Dr Pehl’s be confirmed, it will become possible to destroy bacteria and render a water comparatively pure simply by passing it through a centrifugal machine. The subject is of special interest to brewers, who suffer* perhaps, more than any other manufacturers from the attacks of bacteria, PEIMITITE TELEPHONES.

At the last imeting of the China Asiatic Society at Shanghai an instrument, which was a species of primitive telephone, was presented for inspection. It consisted of two bamboo cylinders from 1? to 2 inches in diameter, and 4in. in length; one end of each was closed by a tympanum of pig-bladder, which was perforated for the transmitting string kept in its place by a knot. This rude instrument is called the “listeningtube,” and is employed for amusement, conveying whispers 40 or 50 feet. It is unknown in many parts of China, the provinces of Che-kiang and Siangan being the only ones where it is employed. Besides this toy, Chinese ingenuity produced, about a century and a half ago, the “ thousand-mile speaker.” This implement is described as a roil of copper, likened to a pipe, containing an artful device j whispered into, and immediately closed, the confined message, however long, may be conv.yed to any distance, and thus, in a battle, recent instructions may be conveniently communicated. It is a contrivance of extraordinary merit. The inventor of the "thousand'mile speaker,” one Chiang Shunsin, of Euichou, flourished during the reign of Kang’hsi, during parts of the seventeenth *ud eighteenth centuries,