Note 241 — SECTION VII. ZOOLOGICAL NOTES (ANIMALS WILD AND TAME)—NOTES ON FLORA—AGRICULTURE AND CATTLE-BREEDING—FISHERIES AND FISHING—INDUSTRY AND EMIGRATION.

The “Napoleon book” (p. 364), gives a sketch of a “mine de criolithe:” one of the veins embedded in granite is eighty feet thick. Mr Walker (Peirce’s Report, p. 3) is mistaken in asserting that cryolite is found only in Greenland, but doubtless the largest known supplies are there, the development being due in great part to American (U.S.) enterprise. The natives used it only in the pulverised state—like quartz—to “lengthen out” their snuff; and similarly the “Red Indians” of the Brazil utilised their diamonds as counters. This double fluoride of sodium and aluminium, popularly called natural soda, is a mineral of ever increasing value; it is employed in the manufacture of soda and soda-salts, hydrofluoric acid, fine glass, and earthenware almost infrangible; the residue makes a flux (“Steven’s flux,” etc.) capital for the treatment of difficult metallic ores. Perhaps the chief use is in the manufacture of aluminium and its alloys, a noble metal which can be carried to white heat before it oxidises, and whose brilliancy is unaltered by sulphuretted hydrogen, water, acids, salts, and organic matter. The price till lately was about one-third that of silver, but increased cheapness has extended the use, especially in coinage and jewellery. Tenacious as silver, sonorous, easily melted and moulded, about as hard as soft iron, and one-third the weight of zinc; it is valuable for watch-cases, mirrors, spectacle-frames, opera and field glasses, hand-bells, pendulum-rods, small weights and balances, chemical apparatus, instruments of precision, and articles where lightness is required. It has also been converted into dinner services and cooking apparatus, in which, unlike tin and copper, it is absolutely harmless. The common form is bronze d’aluminium, with one of that metal to ten parts of copper; the tenacity of the alloy is about that of steel.