780
T H E JOCR-Y.4L OF I - Y D L - S T R I d L - 4 S D E-YGIA\'EERISG
tubes, or similar apparatus, with compressed oxygen or air, are supplied in many works, folds of flannel still seem to be the more general form of respirator.
CHE-MISTRY
j, KO.9
plating may thus be continued until the required thickness is obtained.
THE MELTING POINTS OF ELEMENTS OF ATOMIC WEIGHT WANTED: NEW USES'FOR BROMINE A prize of $2,500 is offered by the Deutsche Bromkonvention G. m. b . H., Leopoldshall-Stassfurt, Germany, t o the discoverer of a process or compound leading t o a new or an increased consumption of bromine. The following are some of the conditions attached to this Competition: The new discovery must represent a technical innovation and must not adversely affect existing uses of bromine. The process must be applied in practice a t the latest one year after the awarding of the prize. The process must, in the opinion of the jury, lead t o a considerable increase in the European consumption of bromine a t a suitable price. Competitors must send in their processes by January I, 1914, a t the latest. THE RADIUM MARKET There has recently been a marked reduction in the prices of radium preparations. Earlier in the year radium bromide sold for $105.60per milligram in Germany; and, in April, a New York firm offered for sale any part of 800 milligrams of radium bromide, gauging from 2 5 per cent to go per cent purity, t o be delivered in tubes of I O to 125 milligrams capacity, a t $go to $100 per milligram. I n July, however, the K. K. Montan-Gesellschaft in Wien. which produces radium salts from pitchblende, made sales at $43.20 t o $52.80 per milligram, depending upon the activity. The recent decrease in price is thus explained in Chemie, 6,No. 1530: During the last three years, mesothorium, as well as radiothorium, began to be employed in place of radium, especially in medicine. Mesothorium is obtainable at a cost of $32.40 per milligram in Germany and, in addition, may be procured four times more active than radium. While the life of mesothorium is short, by mixing it with radium salts a preparation of long life may be obtained. The total production r of radium bromide per year is between 2 and 3 grams. I n ~ g I, the radium preparations produced by the Austrian Radiumpraeparatefabrik amounted to 14.146grams, containing 2 ,647 grams of pure radium chloride, valued a t $2 14,900. The Radium Hill Company conducted ?perations in 1912in Australia which resulted in the productibn of z . 5 milligrams of pure radium bromide; it is reported that 350 milligrams more are in the laboratory in various stages of purification. Recently two American firms have been organized for the preparation of radium salts, etc.; these are the Radium Company of America, of Philadelphia and Sellersville, Pa., and the Radium Chemical Company, of Pittsburgh, Pa. The latter company is marketing radium salts and applicators, radium drinking water, radium bath water, radium compresses, and radioactive earth. ___-THE MANUFACTURE OF COPPER WIRE BY ELECTRODEPOSITION According to the Brass World, W. E. Gibbs has devised a process for the manufacture of copper wire by electrode position. Previous attempts to accomplish this object have been unsuccessful. The Gibbs method requires a fine copper wire as a core for making the desired product, and the additional copper is deposited on i t while i t moves through a tank containing the solution. The fine copper wire is made endless and passed through a regular plating solution containing sulfate of copper and a little sulfuric acid. The wire passes over grooved rollers operated from outside while passing through the tank. After leaving the tank, the wire passes through a small rinsing tank to remove the solution, and then goes to a reel around which it passes a number of times, returning again to the plating tank. The
48 TO 59 Burgess and Waltenbergl have determined the melting points of the refractory elements of the iron group by means of the micropyrometer,* obtaining the following results: Melting point with microMetal pyrometer 1452 '(a) Nickel, . . . . . . . . . . 1449(b) 1477 =k 2 Cobalt.. . . . . . . . . . 1478 f l ( c )
{ {
Probable melting point of pure element , 1452O f 3
Purity' Per cent. 99.836 99.951 99.98
Iron, . . . . . . . . . . . .
*
01
1478O
*
5
1530"
f
5
Manganese . . . . . . . 1255 97 to 98 , 1260' f 20 Chromium ........ I520 98 to 99 1520° to > F e Vanadium.. ....... 1720 97 to 98 1720' * 201 Titanium . . . . . . . . . 1794 12 99.9-k 1795O * 15 (a)Assumed value on platinum strip; also observed value on iridium strip. ( b ) Crucible melts in electric furnace. (c) Crucible melts in electric furnace; also on iridium strip with micropyrometer. ( d ) Five samples all agreeing t o within 3'. f
THE GRANULATION OF SLAG Recently G. Juntzen described a method of granulating slag by means of a jet of air before the German Metallurgical Association. I n this procedure, which has been in use for over a year a t the Buderus Works, where about 1 0 0 tons are produced daily, the slag run from the furnace is conducted through a conduit to a rotating drum 45 feet in length and 6 feet in diameter. Upon entering this drum, it is met by a jet of compressed air, which throws it against the sides, which are kept cooled by the exterior circulation of water; in this way the disseminated
DEVICEFO::
GRASLLATISGMOLTEX SLAG
slag always encounters cool surfaces. Scrapers within the drum prevent adhesion of the slag, which eventually is removed a t the bottom end of the cylinder in small grains, said t o be without lumps. It is claimed that the slag thus reduced is more satisfactory for cement-making than that granulated by water; it is dry and also more dense. Such granulated slag is suitable for use as sand. I n the process of J . T. Bergwith for the granulation of blastfurnace slag, the attempt is made to produce a dry granulated slag, notwithstanding the employment of water.3 1 2
J . Wash. Acad. Sci.. 3, No. 13, 371. Bull. Bureau of Standards, 9, 475. Eng. Min. J.. 96. 5 5 .
