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Ornithological clock
Ornithological Clock.
411
When the materials are used pure, the resulting crystals are of course colorless, but by adding a little of tile fluoride of chromium to the fluoride of aluminum, the colored gems, the ruby, sapphire, or oriental emerald may be produced, the colors depending solely upon the proportions of the chrome used, which, in all eases, must be very small, (except in the green gem, M. Damour having detected 25 per cent. of oxide of chrome in ouvarowite.) The colors produced are identical with those found in nature, and the gems retain their perfect transparency. In some eases rubies and sapphires were produced alongside of each other. The zircons and other analogous minerals were produced in a similar way. Chrysoberyl, with its charaeteristic erystallization, was produced by mixed fluorides of aluminum and glueinum treated as above; zahnite, from the fluorides of aluminum and zinc ; staurotide by substituting silica for the boracic acid, or by heating alumina to a high temperature in a current of gaseous fluoride of silicium. But all the silicates thus prepared arc very basic, containing a very small portion of silica. Rutile was obtained by the decomposition of a fusible titanate, especially titanate of protoxide of tin by silica. " I n making these experiments we often obtained in solution in the tin, a brilliant substance, crystallizing in large metallic plates, separable from the tin by hydro-chloric acid, which scarcely attacks them. This curious material is an alloy of equal number of equivalents of iron and tin. This appearance and chemical properties give it considerable interest."
These researches are valu able not only from their applicability to the arts; in which, the artificial production of the hard minerals will greatly add ~o our facilities; but also by their important bearin~ a~, the theory of the formation of gems and the production of minerals~n nature.
Ornithological Clock.* As botanists have constructed a flower-clock, so (we read in the foreign journals) a German woodsman has recently invented an ornithological clock, by marking the hours of the waking and the first notes ot the little singers. The signal is given by the chaffinch, the earliest riser among all the feathery tribes. Its song precedes the dawn, and is heard in summer from half-past 1 to 2 o'clock, A. M. Next, from 9 to half-past 2 o'clock, comes the black cap, (Sylvia atricapilla), whose warblings would equal those of the nightingale if they were not so very short. From half-past 2 to 3 o'clock the quail is heard. From 3 to half-past 3 the hedge-sparrow. Then from half-past 3 to 4 o'clock, we have the blackbird, the mocking-bird of our climates, which imitates all tunes so well, that M. Dureau de La Malle made all the blackbirds of a French canton sing the Marseillaise hymn, by letting loose a blackbird which had been taught that tune. From 4 to half-past 4 o'clock the lark pours forth its melodies ; from half-past 4 to 5 o'clock the black-headed titmouse is heard. Lastly from 5 to half-past 5 o'clock, the sparrow~ the gamin of the skies, awakes and begins to chirp. *From the London Athenaeum, September~ 1857.
411
When the materials are used pure, the resulting crystals are of course colorless, but by adding a little of tile fluoride of chromium to the fluoride of aluminum, the colored gems, the ruby, sapphire, or oriental emerald may be produced, the colors depending solely upon the proportions of the chrome used, which, in all eases, must be very small, (except in the green gem, M. Damour having detected 25 per cent. of oxide of chrome in ouvarowite.) The colors produced are identical with those found in nature, and the gems retain their perfect transparency. In some eases rubies and sapphires were produced alongside of each other. The zircons and other analogous minerals were produced in a similar way. Chrysoberyl, with its charaeteristic erystallization, was produced by mixed fluorides of aluminum and glueinum treated as above; zahnite, from the fluorides of aluminum and zinc ; staurotide by substituting silica for the boracic acid, or by heating alumina to a high temperature in a current of gaseous fluoride of silicium. But all the silicates thus prepared arc very basic, containing a very small portion of silica. Rutile was obtained by the decomposition of a fusible titanate, especially titanate of protoxide of tin by silica. " I n making these experiments we often obtained in solution in the tin, a brilliant substance, crystallizing in large metallic plates, separable from the tin by hydro-chloric acid, which scarcely attacks them. This curious material is an alloy of equal number of equivalents of iron and tin. This appearance and chemical properties give it considerable interest."
These researches are valu able not only from their applicability to the arts; in which, the artificial production of the hard minerals will greatly add ~o our facilities; but also by their important bearin~ a~, the theory of the formation of gems and the production of minerals~n nature.
Ornithological Clock.* As botanists have constructed a flower-clock, so (we read in the foreign journals) a German woodsman has recently invented an ornithological clock, by marking the hours of the waking and the first notes ot the little singers. The signal is given by the chaffinch, the earliest riser among all the feathery tribes. Its song precedes the dawn, and is heard in summer from half-past 1 to 2 o'clock, A. M. Next, from 9 to half-past 2 o'clock, comes the black cap, (Sylvia atricapilla), whose warblings would equal those of the nightingale if they were not so very short. From half-past 2 to 3 o'clock the quail is heard. From 3 to half-past 3 the hedge-sparrow. Then from half-past 3 to 4 o'clock, we have the blackbird, the mocking-bird of our climates, which imitates all tunes so well, that M. Dureau de La Malle made all the blackbirds of a French canton sing the Marseillaise hymn, by letting loose a blackbird which had been taught that tune. From 4 to half-past 4 o'clock the lark pours forth its melodies ; from half-past 4 to 5 o'clock the black-headed titmouse is heard. Lastly from 5 to half-past 5 o'clock, the sparrow~ the gamin of the skies, awakes and begins to chirp. *From the London Athenaeum, September~ 1857.