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Otago Witness, Issue 2331, 3 November 1898, Page 54

SCIENCE NOTES.

I — An Englishman lias invented a memorandum clock which will doubtless prove very valuable to the busy business man, who is eternally forgetting his appointments, etc. A mechanism is provided whereby the clock can be " loaded," as it were, with memorandum, which will only come into sight when the precise moment at which they are timed to appear arrives. Thus, by glancing at the clock, the busy man can tell at a glance what is to be done next. — Speaking with strict accuracy, instead of presenting an unchanging face towards us, the moon appears to be never still, but always rocking backwards or forwards, falling towards us or away from us, and by the /» mount of these variations — small, it is very true— regions of the hemisphere turned away from us are disclosed. They are placed, unhappily, in the situation best calculated to defeat curiosity. We are permit led to lake just a glimpse of the " other side," but to bring away only the minimum of information as to its condition. Perhaps it is rash to say we shall never know more of the " other side" of the moon, so marvellous have been the recent discoveries in astronomy. Some day, perhaps, new discoveries after the the manner of Rontgen rays may enable us to get a photograph through the moon. Short of that, we must needs wait foi some stray visitor from outer space to come into collision with the moon and turn it round, in ordcT to enable us to satisfy 0111 curiosity ; and patience may well be stimulated by the knowledge that the results of such a collision should it ever occur would in all probability bo not less disastrous to the earth than to the moon itself.— Windsor. —We have received a paper, read before the Jewish Board of Guardians by Dr A. Gaster, which gives some valuable statistics relating to tuberculous disease. The author's obiect was to &ct Imfore a body of laymen

a succinct and popular account of tuberculosis, together with an abstract of the conditions of it* spread among the Jews. He gives a short account of the tubercle bacillus and its relation to the disease, laying particular stress on the retention of virulence for many months by bacilli dried at a temperature of 725deg C, and on their continued activity after prolonged immersion in water or burial in earth. Emphasis is properly laid upon the extreme danger to the community resulting from the continuance of their ordinary occupations by phthisical subjects who are not ill enough to be admitted into hospital. Dr Gaster states that among Jews the disease mainly affects the intestines, and is due to the consumption of infected food and milk. This view is certainly not that held by most authorities. Pulmonary phthisis is generally regarded as the commonest form in Jews as in Gentiles, and it must be remembered that the Talmudic laws as to the inspection of meat render it almost impossible for a tuberculous carcase to be used as human food. The author quotes some valuable statistics showing that Jews suffer from consumption only about half as often as non- Jews. His results are based upon burial returns of the United Synagogue from 1889 to 1893, as compared with those of the Registrar-general. He expresses his conviction, which is perhaps rather more patriotic than scientific, that the favourable condition of the Jews is due to race influences. He is, nevertheless, alive to the importance of preventing tuberculosis from seizing upon the Jewish race, and he gives some excellent rules to this end ; those relating to the bringing up of children born of a tuberculous stock are particularly commendable. The Jewish Board of Guardians is doing good work in the interest of sanitation for the whole of the East End of London by the leaflets which it issues on this and allied subjects.— British Medical Journal. — Human talk can now be had over a tefephone at a distance of 1800 miles, and conversations a distance of 1500 miles are common. There are now nearly 1,000,000 telephones connected with this country's service, employing a capitalisation of about 100,000,000d01. Every day about 17,C00 employees- make on an. average more than 3,000,000 telephone connections. Mr C. "Wood Davis, an American labour leader, maintains that machines are enabling us to dispense with labour at such a rate that there will soon be no work left for anybody to do with his two hands. Among other illustrations of the progress of labour-saving machinery, he tells us that " the seed potato is cut by one machine and planted by_ another, while the product is dug by a third ; that the ' self -feeder ' of the threshing machine displaces two men ; while ' blaststackers ' and gasoline engines will, when in general use, reduce the labour of 75,000,000 acres of grain annually in the equivilent of constant work for 150,000 men ; that the ' two-row ' cultivator will displace labour in cultivating 110,000,000 acres of rowed crops in the equivalent of constant employment for 130,000 men ; that in the pastoral regions the ' hand-shearer ' has been displaced by machines making 3000 clips per minute." —The greatest known depths of the sea arc in the South Atlantic Ocean, midway between the Island of Tristram d'Acunha and the mouth of the Rio de la Plata. The bottom was there reached at a depth of 40,236 ft, or seven and three-fifths miles. In the North Atlantic Ocean, south of Newfoundland, soundings have been made to a depth of 4580 fathoms, or 27,480 feet, while depths equalling 34,000 feet, or six miles and a-half, are reported south of the Bermuda Islands. The average depth of the Pacific Ocean, between Japan and California, is a little over 2000 fathoms ; between Chili and the Sandwich Islands, 2500 fathoms ; and between Chili and New Zealand, 1500 fathoms. The average depths of all the oceans is from 2000 to 2500 fathoms. — Ozone has never yet been obtained as a gas in the pure state, but from the properties of mixtures containing it we cannot doubt that gaseous ozone would be blue in colour, and condense at low temperatures to an indigo-blua liquid, which explodes violently on contact with olefiant gas. The ozone in mixtures, such as are produced by the electrification of air or oxygen, is very unstable, being resolved into common oxygen with explosive violence if suddenly compressed without previous cooling ; and even under atmospheric pressure it cannot long be preserved except at rather low temperatures, 'lms characteristic instability of ozone is at once the cause of its most interesting properties and of its possible usefulress. Molecules of common oxygen contain but two atoms of the element, whilst the molecules of ozone contain three such atoms, and it would seem that the atoms hold- together much less firmly in the larger molecules than when they are united in pairs •, consequently ozone acts as a powerful oxidiser, readily giving up part of its oxygen to oxidisable substances, whilst the rest returns to the ordinary form of the element, except in certain cases when it is completely absorbed. Ozone wa-s first noticed in air which had been exposed to the sparks of electrical machines ; but only very small quantities can be obtained in this way, and it is better to expose the air to a sort of electric rain composed of showers of very fine sparks, such as were employed by Andrews, or to the so-called silent discharge in one of the various forms of the " Siemens' s induction tube."

— Within the Antarctic circle there has never been found a flowering plant. — The extent to which ball bearings are now employed is shown by the importation into the United States of at least 200,000,000 balls a year. Recently a company has been formed in Pennsylvania for the erection of large works at chat place for the manufacture of steel balls. The plant is io have a capacity equal at least to the importation demands of last year— namely, 200,000.000 balls. Floriline !— For the Teeth and Breath— A few drops of the liquid "' Floriline" spnnIchd on a wet tooth brus-ii produce a pleasant lather, which thoroughly cleanses the teeth from all parasites and impurities, hardens the gums, prevents tartar, stops decay, gives to the teeth a peculiar pearly whiteness, and a delightful fragrance to the breath. It removes aM unpleasant odour arising from decayed teeth or tobacco smoke. " The Fragrant Floriline, being composed in part of honey and sweet herbs, is delicious to the taste, and the greatest toilet discovery of the age. Price 2s 6d of all chemists and perfumers. Wholesale depot, 33 Farriucdon road, tendon, England.— Advt.