scientific.

Waikato Times, Volume XXIII, Issue 2271, 29 January 1887, Page 2 (Supplement)

scientific.

Compass Errors.—An article in the Liverpool Journal of Commerce deals with the interesting subject of compass errors, and after enumerating a number of incidents wherein derangements in the needle have beeu noticed upon the approach of an umbrella, of Volunteers with rifles, of men wearing electric belts, and, finally, of men impregnated with iron tonics and other metallic solutions, concludes as follows: "There ore so many causes to make a compass go wrong, that those who profess to know everything have, .it is evident, much to learn. Masters of ships, whose certificates are liable to bo cancelled or suspended, should never rely solely on the compass. They are useful and iodisensable navigation instruments, but. they may be misleading, and require supplementing by the log, the lead and the lookout."—Electrical Review.

A Prolific Copper Mink in Canada. —One of the most wonderful copper mines in the world has, says a Canadian contemporary, been discovered near Sunbury Junction, Ontario. Its wonder consists in the fact that it is by far the largest mine of the valuable ore ever yet brought to light by a prospector, and its proprietor,, Mr Ritchie, and the country generally will reap vast advantage from this new source of mineral wealth. The copper ridge, which is situated a few miles from Sunbury depot, is four miles in length, 1,500 feet wide, and 200 feet deep. The percentage of pure copper is very large and no purer ore has yet, in the opinion of competent authorities, been discovered. Coal Tar Qcinine.—Professor Fischer, of Munich after an extended research on the nature and properties of quinine, has discovered that a substance inay be extracted from coal-tar that exercises on the human organism an action identical with that of quinine. The substance appears as a white crystalline powder. Administered iD cases of fever, it has the effect of rapidly lowering the temperature, and its efficacy in this respect is stated to be so remarkable as to permit the use of ice to b« dispensed with ; in the stomach, the wonderful powder assimilates with even greater facility than does quinino.— Engineering and Mining Journal.

A New Remedy in Heart Disease. — Dr. Von Hoist says that nitro-glycerine is very useful in heart disease, especially when there is no serious organic change. In angina pectoris the drug gives relief and sometimes produces a permanent cure, and recommends it in preference to camphor or musk where weakness of the heart threatens immediate danger. He uses a 1-per cent, alcoholic solution, and administers from one to six drops three times a day. A Curious Rkmkoy.—A n#w cure for consumption has been originated by a Teutonic doctor. He makes his patients pass the night in the open air of the Thuringian forest, well wrapt up, and sleeping in light hammocks so as to avoid all damp from the ground. A watchman keeps off any intruders who might disturb the night's rest, and hitherto the experiment has proved wonderfully successful.

A New Coffke-tbee. —The Giornale d' Agricultura e Commercio for August reports the discovery in West Africa of a new variety of coffee-plant, whose berry appear* greatly to resemble that of Arabia in appearance and flavour. It grows, however, not on a shrub but on a tree nearly 7 feet high, which develops rapidly and yields an abundant crop. Arrangements are already being made for introducing its cultivation in favourable localities.

For Cleaning Grease Spots.—Equal parts of strong ammonia water, ether and alcohol, form a valuable cleaning compound. Pass a piece of blotting paper und<»r the grease spot, moisten a sponge, first with water to render it '' greedy," then with the mixture, and rub with it the spot. . In a moment it is dissolved, saponified and absorbed by the sponge and blotter. Wood Powder as an Explosive.— Wood powder has recently been introduced as an explosive in the Belgian army in place of dynamite. The powder is obtained by treating ordinary sawdust with a mixture of nitric and sulphuric acids, which is afterwards formed into cartridges by means of powerful presses. To protect these cartridges from moisture, they are afterwards covered with paraffine paper. The instantaneous production of the gases arising upon explosion causes the air in contact with the face surface of the cartridge to act to some extent as a light tamping, and the power of the explosion is directed to the other face. In comparative experiments made with wood powder and dynamite, it was ascertained that, for equal weights, charges of the first substance were at least as powerful as those of the second, and the results were more regular. Influence of Magnesia in Portland Cements.—G. Lechartier : The cements employed in certain cases that the author has examined were mixtures of Portland cement with magnesia, which behaves at first like an inert body. By alow degrees, the magnesia becomes hydrated long after the cement has set, while it increases in bulk, producing an expansion and the consequent destruction of works, the solidity ef which appeared established. These destructive changes take place the more rapidly the more directly the water acts upon the cement and penetrates into their mass.

Tobacco. —The Lancet makes a distinction between what it calls the use and the abuse of tobacco. The man who can say, " I always know when I have smoked enough—if Igo beyond the just limit I lose my power of prompt decision," is one, it suggests who had better not smoke al all ; but '• a moderate use of tobacco soothes the senses, and leaves the mental faculties free from irritation, and ready for calmly clear intellectual processes " When this is not the effect produced by smoking, the " weed" had better be eschewed.

Submarine Photography. — Two Frenchmen, Bonfante and Maisonneuve, have undertaken experiments to facilitate the photography of submarine objects. If a diver could be supplied with h suitable camera, and perhaps also with a sufficiently strong artificial light, he could bring to t.he surface far more satisfactory reports of what was beneath thaD any verbal descriptions, however honest and accurate, could possibly supply.

A Railway Church.—The Russians perform such long' journeys by railway that they have started a railway church, which is attached to the long-distance trains.