_Sulphur._—Often called brimstone. A mineral of yellowish color. Soluble in turpentine, fat oils, bisulphuret of carbon and hot liquor of potassa. With oxygen it forms sulphuric and sulphurous acids, and with the metals it combines as sulphurets or sulphides. It is an essential ingredient in gunpowder, and the gas arising from its combustion is employed in bleaching straw and woolen goods. _Tartar, Salts of._—See potash. _Turpentine._—An oleo-resinous substance as flowing from several species of pine, larch and fir trees. Oil of turpentine is obtained by distilling the crude turpentine. _Umber, Burnt._—See Burnt Umber. _Venice Turpentine._—A liquid resin which exudes from the larch tree. The Venice turpentine usually met with is turpentine to which is added a quantity of black melted resin. _Verdigris._—A green oxide of copper, very poisonous. The white of eggs is an antidote for the poison, when taken into the stomach. _Vitriol, Blue._—Called sulphate of copper. See Blue Vitriol. _Vitriol, Green._—Sulphate of iron. See Copperas. _Vitriol, Oil of._—See Acid, sulphuric. _Whiting, Spanish._—See Spanish Whiting. CHAPTER XLI. CALIBRES OF GUNS, RIFLING, TWIST OF RIFLING, ETC. _European Guns._—The Enfield Rifle; Muzzle Loader, Cal. 577; 3 grooves; regular twist, slightly deeper at breech than at the muzzle; rifling one turn in 6 feet 6 inches. The Purdy Rifle, Muzzle Loader; Cal. 650; 4 grooves; increasing twist, commencing at one turn in 6 feet and ending at one turn in 4 feet 9 inches. The Wilkinson Rifle, Muzzle Loader, Cal. 530; 5 grooves with a regular twist of one turn in 6 feet 6 inches. The Lancaster Rifle, Muzzle Loader. Bore smooth and elliptical diameter at muzzle; greater axis, 550; lesser axis, 540; greater axis at breech, 557; lesser axis, 543. The twist is one quarter turn in whole length of barrel. Length of barrel, 39 inches. The Snider Rifle, Muzzle Loader; Cal. 577; 5 grooves, one turn in 4 feet. The Whitworth Rifle, Muzzle Loader. Polygonal or hexagonal form of bore. Rifling, one turn in 20 inches. Bore, 564 across the flats. 568 across center of flats. The Jacobs Rifle, Muzzle Loader; 4 grooves; loads and grooves equal. Rifling four-fifths turn in 24 inches. The Turner Rifle, Muzzle Loader. Bore, 568. Rifling Turner’s Patent, one turn in 4 feet. The Rigby Rifle, Muzzle loader. Rifling 6 grooves; one turn in 4 feet. The Boucher Rifle, Muzzle Loader. Bore hexagon with angles, rounded off so as to form shallow grooves, 608 deep in center. Bore, 570. Rifling one turn in 3 feet 3 inches. The Prussian Needle Gun, Breech Loader. Rifling 4 grooves, one turn in 40 inches. The Chassepot Rifle, Breech Loader; Cal. 433; rifling 4 grooves, turning from left to right, one turn in 21½ inches. The Snider Enfield, Breech Loader. Rifling 3 grooves slightly deeper at breech than at the muzzle, one turn in 78 inches. Diameter, 577. Depth of rifling at muzzle, 05. At breech, .13. Width of grooves three-sixteenths inch.