Page:Popular Science Monthly Volume 18.djvu/299

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The Deep Valley of the Caribbean Sea.—Commander J. R. Bartlett, of the Coast-Survey steamer Blake, has ascertained some interesting facts in regard to the depths of the western part of the Caribbean Sea. The data he has obtained make it probable that a large portion of the supply for the Gulf Stream passes through the "Windward Passage" between Cuba and San Domingo, and that the current extends in it to the depth of 800 fathoms. The temperature, of 3912°, which was indicated at all depths below 700 fathoms in the Gulf of Mexico and the western Caribbean, was not obtained here. Elsewhere, in these seas, the temperature decreased from the surface to 3912° at 700 fathoms or less, and remained constant at that temperature for all lower depths. At greater depths than 600 or 700 fathoms the bottom was always found to be a calcareous ooze composed of pteropod shells with small particles of coral. An immense, deep valley was found to extend from between Cuba and Jamaica to the westward, south of the Cayman Islands, well up into the Bay of Honduras. It has a length of 430 miles, and a general breadth of 105 miles, with a depth nowhere of less than 2,000 fathoms, except at two or three points where the summits of submarine mountains rise to near the surface. Within 20 miles of Grand Cayman it attains an extreme depth of 3,428 fathoms; this island is therefore, to the bottom of the valley, as a mountain 20,000 feet high, and Blue Mountain, in Jamaica, rises 29,000 feet above the bottom, or as high as the highest of the Himalayas is above the level of the sea. The deepest part of the valley has been named the "Bartlett Deep."



Mr. Rogers Field, in a recent lecture on house-drainage at the Parkes Museum of Hygiene, condemned all forms of water-traps as a means of excluding sewer-gas from dwellings, on the ground that they allow the gases to pass through them by the water absorbing it on one side and giving it off on the other. In his opinion, the only sure way to keep these gases out of the house is by thorough ventilation and disconnection. Efficient ventilation moans a continuous current of fresh air through the drains and pipes, but even then perfect security can only be obtained by cutting off direct communication between the sewer and the house-drains.

The last annual report of the New Haven Board of Health contains a valuable letter addressed to the Common Council of that city, by the President of the Board, Professor William H. Brewer, of the Sheffield Scientific School, setting forth in a forcible way the financial advantages of a thorough system of sanitary administration in towns and villages. This letter should be in the hands of all the village trustees in the land, many of whom may be reached by money considerations when mere questions of life and death would scarcely arrest attention.

In its crusade against the London shop-keepers for obliging their saleswomen to stand continually during business hours, the "Lancet" is disposed to lay a part of the blame on the patrons of these establishments. It thinks if there were any real sympathy, on the part of the public, for the young persons who are made to suffer by the system of standing, it would long ago have been brought to a summary close. We sometimes hear of women having a special faculty for nursing the sick: they should show in this matter that they have the humanity to avoid the creation of needless disease.

Mr. Nilson has prepared a quantity of the oxide of the new metal ytterbium, or ytterbine, and finds the atomic weight of the metal to be 17·301. Ytterbine appears in the state of an infusible white powder of a density of 9·175, insoluble in water, but easily dissolved in acids, even when diluted, at a boiling heat; but, when cold, they attack it with difficulty, even if concentrated. The solutions are colorless, and show no absorption rays in the spectrum. The earth and its salts do not communicate any color to flames; but the chloride gives a very bright spectrum with the electric spark.

A new remedy for neuralgia has been introduced into England from the Feejee islands. It is called tonga, and is brought in the shape of fragments of woody fiber, bark, and leaves, broken up into pieces so small as to make it hard to identify them botanically, mixed and done up into balls of about the size of an orange. To prepare it, the ball is soaked in cold water for about ten minutes, when the infusion is drawn off and a claret-glass of it is taken three times a day. The ball is then dried and hung up, and can be used over and over again for a year. The principal constituent of the remedy appears to be the stem of a species of Raphidophora.

M. Lortet, who has been studying the fauna of the Lake of Tiberias, reports that