SCIENCE, MECHANICAL INVENTIONS, ETC.

New Zealand Herald, Volume XXXVIII, Issue 11644, 4 May 1901, Page 6 (Supplement)

SCIENCE, MECHANICAL INVENTIONS, ETC.

MOUTH - BREATHING. The nose is the first of the organs of respiration, and unless its functions are well performed the whole breathing process is deranged. The nostrils are divided into several compartments by bony projections, covered with mucous membrane, and the volume of air in entering is broken up into several streams, so that all of it conies in contact with the lining membrane. This warm and moist membrane catches (says the Youths' Companion) the dust and other impurities, and warms the air, so that it will do no harm in coming in contact with the more, delicate membrane in the bronchial tubes and lungs. When the nose is stopped up from any cause one must breath through the mouth, and if this is continued for any length of time the general health will inevitably suffer. The mouth itself suffers first. The mucous membrane loses its moisture, and becomes inflamed. The air is neither warmed nor purified, and it irritates the lining membrane of the air-passages all the way down to the lungs, so that a condition of sluggish inflammation is excited. But the general effects are more serious than the local. One who is a mouthbreather never gets enough air. During the clay he suffers less in this respect, for the nerve centres are more active, and force the respiratory muscles to act more energetically ; but at night this~vigilance is relaxed, and the amount of inspired air is greatly reduced, and all the tissues suffer for want of oxygen. THERAPEUTIC ACTION" OF LIGHT. Dr. P. Garnault has recently rend a paper before the French Academy of Science dealing with the therapeutic action of light. In a number of cases he has used this treatment with success. His attention was first called to the subject by M. Trouve, who was among the first to bring out this action of light. In 1893 he observed that a workman afflicted with rheumatism was completely cured after having remained for 48 hours in the vicinity of a very intense light used for an electric fountain. Since then it has been observed that in works where electric soldering is carried on, this being accompanied by great luminous intensity, the workmen cease to be affected with gout or rheumatism. Chronic catarrh of the nose may be also treated with success by the application of light, accompanied by vibratory massage. This treatment was also applied in cases of deafness, accompanied or not by humming noises in the ear; the apparatus used consisted of two ten-volt lamps, provided with reflectors, and applied to each ear by a curved spring passing round the head : in some cases the action of heat was eliminated by placing alum screens in front of the lamps. In three such cases were marked diminution of the humming noises and an improvement of the hearing; other eases Without the use of the alum .screen were also successful. The most complete observation was made upon a person thirty years 1 of age who had undergone, the year before, an operation in which the tynpannum and small bones of one ear had been removed: on the operated side the intensity of the humming noises had been greatly reduced, but on the other side they were very marked. These were made to disappear by a series of applications of light. Th«y re-appeared after a severe cold contracted by the patient, but were again made to disappear by a second treatment. In twelve cases of deafness the application of light brought about good results. AP.SENTC IN BEER. The commission of experts, consisting of Sir Lauder Brimton, Dr. Thomas Stevenson, Dr. A. P. Luff, Mr. A. Gordon Sulamon, Mr. Samuel Buckley, and Mr. J. Fletcher Moulton, K.C., M.P., appointed by the Manchester Brewers' Central Asoci'ation, have presented a report to the association. The commission have thought it necessary to investigate, and determine what is the most suitable method of testing beers for arsenic, and recommend the Reinseh test in preference to all others at present known, because their investigations have satisfied them that it is the best and most reliable test for arsenic in beer. The mode of performing it is as follows:—Take 200 c.c. of the beer in a porcelain evaporating dish. Raise the liquid to the boiling point, and then add 30c.c. of pure concentrated hydrochloric acid. Insert a piece of pure, bright, copper foil, about ,|in by £in in size, and keep the solution gently boiling for 45 minutes. If at the end of that time the copper remains bright and red, the beer is free from arsenic. If a. deposit is obtained on the copper, the foil is to be washed successively with water, alcohol, and ether (care being taken that these are pure), dried at a temperature not exceeding lOOdeg., C, and subjected to slow sublimation in a thin reduction tube of small section, and not less than two inches long, the upper portion of which should be warmed before the sublimation begins. For the purpose of the sublimation a small spirit-lamp flame should be used. If any sublimate is obtained, it must be examined under a magnifying power of about 200 diameters. Any sublimate which does not show well-defined octahedral or tetrahedral crystals is not to be considered arsenical.

I N.B.—lt must be borne in mind that the [ blackening of the copper or a deposit there- | on from the preliminary operation does not denvonstEafe the presence or arsenic in beer. Abundant blackening and deposit may be obtained from the purest beer.—Chemist and Druggist. THE NEW TELEPHONE. Automatic telephone " calling" lias come into vogue in parts of the enterprising West, and in abolishing the telephone girl deprives the American humorist of a favourite theme for levity. Calling is effected in the following manner:—On each telephone set there is a dial containing figures from oto 9. This dial may be revolved freely by the hand in a clockwise direction. A number is called by successively bringing the numerals of which it is composed into the lowest position, beginning with the lefthanded numeral. Finger-holes are placed opposite each figure for the easy manipulation of the dial. When the figure is brought into the lowest position and the dial released, it flies back to its original position of rest, when the second figure is brought to the lowest position, and so on.. For instance, in gelling 4231, the "4" is first brought to the lowest position, then the dial released; then (he "2," "3," and "1" successively. A pressure of'-the button on the telephone set. closes a local primary battery circuit, and rings the bells of both the caller and the number called. Before making a call the receiver is removed from its hook. It is asserted that a second is sufficient time to bring any figure on the dial to its lowest position and allow its return, and one second is ample time to produce a ring at both stations, so that live seconds is' sufficient to effect a connection.—London Leader.

JIACTTCRTA IX MTT.K. Milk under normal healthy conditions contains no bacteria whatever as it issues from the cow ; if due precautions of cleanliness, etc., are observed milk may be obtained absolutely sterile, or, in other words entirely devoid of bacterial life. Such'milk has frequently beer, procured from cows in cases where it litis been required in its natural state, free from bacteria, for experimental purposes. Some highly interesting investigations bearing upon the question of the bacterial pollution of milk have recently been made in Germany, at the Agricultural' School of 01tuna, on (he microbial contents of the air under different conditions in the buildings where cows are kept. ° _ These researches arc of great practical importance, inasmuch as they clearly indi cote the nature of some of the circumstances which affect the purity of our milk supplies the air—a quart being examined each timewas tested at various times, and at various levels, iu the cowsheds, with the following results:-At about oft above the floor, after hay and straw had been supplied to the cattle, an average of 3193 bacteria, were loimd, the highest figure obtained beta" 6000; at a he.gnt of 30in above the floor when the midday milk was being drawn! 1448 were found ; when the cows were rest' nig at midday the air contained just above he floor an average of 1210, while beneath the body of the cow the average number of germs found was 3200. These' results point very clearly to the uudesirabilitv of milkino operations being carried on just after the cows; have been supplied with hay and straw the air being then full of dust particles and heavily charged with bacteria, and the milk becoming in -.tonsequence gorrespondinglr laden, with germ life., ° "