Rensselaer Union, Volume 8, Number 3, Rensselaer, Jasper County, 7 October 1875 — MECHANICAL AND SCIENTIFIC. [ARTICLE]

MECHANICAL AND SCIENTIFIC.

—Mention is made in tlie Naturalist of two cases of albinism recently observed in Ashes. One was a haddock, taken off Barngat, May 7. The fish was thirty-one inches long, and, instead of the usual tints of brownish-gray, its general hue was a pinkish-white with a pearly luster. The other specimen was a common eel taken at Noank, Conn., in December, 1874. The colors of this were a dull, pale yellow above, and nearly pure white beneath. Instances of albinism are not uncommon among European eels, but they are seldom met with on our coasts. The museum of the Peabody Academy of Sciences contains a sample of both the above-mentioned albinos. —A film of sulphate of lead is found to afford an excellent protection for the metal against the action of water. In some experiments made in this direction lead pipes were coated internally with sulphide, according to the well-known Schwarz method, by the action of a solution of sulphide of sodium, and were subjected, at the same time with others not so treated, to the action of rain, snow, distilled and ordinary Paris city water. After the first day lead was detected in all cases in the water from the ordinary pipes, except the city water, and in it also alter several days. On the other hand, in no case did the water from the pipes treated with sulphide afford a trace of lead within three months, and with access of air.— N. Y. Sun. —There are 209 specimens of ferns native t 6 New r Caledonia, an island, in the South Pacific Ocean having an area of 200 miles in length by thirty miles in breadth. Of these ferns eighty-six are peculiar to New Caledonia, and the remainder are common to it and other islands in the Austral seas. From a study of the distribution of these ferns M. Eugene Fournier arrives at the conclusion that New Caledonia, New Holland and New Zealand were at one time united by means of Norfolk Island and other submerged islands. This hypothesis explains the presence in countries differing in climate of species belonging to homogeneous groups that could not have been transported by currents or by other extraneous agents. —The pressure of the atmosphere at the level of the sea has given rise to a great many experiments tending to scientific results, not a few ofwhich have elucidated important truths, while others have been merely curious in their developments. It is a singular and not very well-known fact that, as the boiling point of water is lowered in proportion to the increase of elevation, people living high up in the world are compelled to do without boiled meats and vegetables, and to have their food roasted or baked, since the water cannot be heated sufficiently to cook food. Darwin tells of an amusinglnstaucc of the result of the diminished pressure of the Andes. His companions tried for some hours to boil potatoes, and though the water bubbled vigorously the refused to be cooked, and the result was attributed td the bewitched pot —An ingenious as well as simple in-

strument for testing mineral oils, constructed so as to enable one to compare at once the expansion of any oil to be tested with that of a standard safe oil, both being subjected to the same degree of heat, is coming into general use, and must prove a valuable safeguard against explosion. This apparatus consists of a case holding two bottles furnished with glass tubes of equal here. Irt one of these bottles is placed the oil which serves as the standard of comparison, and in the other, to the same height in- the tube, is placed the oil to be tested. The bottles are mounted upon a wooden support, suitably graduated. In practice it is inserted in a vessel of water of a temperature of 110 degrees, and the conclusion respecting the safety or danger of the article is drawn from the cautionary words upon the support behind the tubes.