Page:Popular Science Monthly Volume 49.djvu/446

428 and one of the most famous of the old South Sea captains, William Dampier, a man who knew more of the Spanish Main and of the Pacific than any one living. He was engaged to accompany the expedition as pilot. They started in 1703, and the voyage lasted three years. In February, 1709, while lying off the island of Juan Fernandez, they observed a light on the shore, and several days later, after the abatement of a storm, which prevented their earlier landing, they went on shore, where they found the original of Defoe's Robinson Crusoe. He was clothed in goat skins, and "seemed wilder than the original owners of his apparel." His name was Alexander Selkirk, a Scotchman, who had lived alone on the island for four years and four months. Captain Thomas Dover returned from the South Seas in 1711, a wealthy man; his subsequent career is only imperfectly known. In 1721, however, he was admitted licentiate of the Royal College of Physicians, a qualification which enabled a man at that time to practice in and six miles around Westminster. In 1732 he published a work entitled The Ancient Physician's Legacy to his Country, in which, he says on the title-page "the extraordinary effects of mercury are more particularly considered." On page 18 is given the formula of his famous powder: "Take opium one ounce, saltpetre and tartar vitriolated each four ounces, ipecacuanha one ounce. Put the saltpetre and tartar in a red-hot mortar, stirring them with a spoon until they have done flaming. Then powder them very fine; after that slice in your opium, grind them to a powder, and then mix the other powders with these. Dose, from forty to sixty or seventy grains in a glass of white wine posset, going to bed, covering up warm, and drinking a quart or three pints of the posset. Drink while sweating." He says that some apothecaries have desired their patients to make their wills and settle their affairs before they venture upon so large a dose as sixty or seventy grains. "As monstrous as they may represent this, I can produce undeniable proofs where a patient of mine has taken no less a quantity than a hundred grains and yet has appeared abroad the next day." Dover continued to practice in London, and in the seventh edition of The Ancient Physician's Legacy there is a letter to him from Catherine Hood, in which she speaks of having consulted him in 1737. He is stated by Munk to have died in 1741 or 1742.

Sisal in the Bahamas.—Sisal fiber which is next in importance to hemp in rope-making, derived its commercial name from the port of Sisal, from which it was originally shipped in the Bahamas. In Yucatan the plant is called ''henequen. Agave sisalana,'' which is its botanical name, had its original home in Mexico; it belongs to the same family as the well-known century plant. On account of its value as a fiber-producer it has now been widely distributed in tropical and subtropical countries. It does not require a rich soil, and can get along with surprisingly little water. The plant is best propagated by means of suckers, which it produces abundantly; they are allowed to reach sixteen or twenty inches in height and are then "lifted" and the roots trimmed and some of the lower leaves removed before resetting. Leaves fit for cutting are produced in three or four years. During the first season of yielding, however, only a few of the larger leaves are removed; subsequently ten or fifteen leaves are cut from each plant. The cutting is done from one to three times a year. The leaves are cleaned by a machine which turns out from one half to one ton of fiber a day; the cleaning should be done within a few hours after the leaves are harvested, as the fermentation which soon starts up in the saccharine matters surrounding the fiber very soon discolors and seriously weakens it. When cleaned before fermentation has set in, the fiber is perfectly white; after passing through the machine it is hung out in the sun to dry, and when dry tied up into bales of three hundred and fifty to four hundred pounds each. An acre of land with six hundred and fifty plants will yield from twelve hundred to fifteen hundred pounds of fiber per annum, the price of which has varied from £50 per ton in 1889 to £13 in 1895. In March, 189(5, it was quoted at £17. A plantation lasts about fifteen years, if carefully cared for. It is necessary, however, to be continually replacing individuals that have "poled." This is the supreme effort in the life of many plants of the agave tribe, and with it they complete their life history.