METALS. 



513 



316 cubic feet, and, since the average amount of tin 

 on tin plate is five per cent., it requires 122.4 IDS. 

 of chlorine to treat one ton, or almost twice as much 

 as will fill that space. There are obtained 222 Ibs. 

 or 12J gallons of anhydrous bichloride of tin and 

 1 900 Ibs. of iron. As regards the cost of chlorine 

 gas, 100 Ibs. require theoretically 135 Ibs. of black 

 oxide of manganese, 165 Ibs. of salt, and 310 Ibs. of 

 oil of vitriol. 



As to the condensation of the vapor of bichloride 

 of tin, five pounds are condensed per square foot per 

 hour. Experience proves that a coil of 50 feet length 

 and 2? inches diameter will completely condense the 

 vapor cooled from one ton of clippings. The dura- 

 tion of the process is from five to six hours. 



Preparation of Tellurium. The rare metal 

 tellurium is thus obtained by Mr. A. Lowe from 

 the ore Tellur-schlieche : He treats it first 

 with dilute hydrochloric acid, and then with 

 strong sulphuric acid, as long as any reaction 

 takes place. The ore is then thrown into water, 

 to which some hydrochloric acid has been added 

 to dissolve all the tellurous acid. Afterward 

 the liquor is decanted from the residue, and the 

 tellurium is precipitated by adding metallic 

 zinc. The residue is fused to a regulus with 

 lead; and this regulus containing all the gold 

 and silver is submitted to the usual treatment 

 for the separation of those metals. Sch welter 

 recommends the following process : 



Treat with dilute hydrochloric acid as long as car- 

 bonic-acid gas escapeSj and then add strong hydro- 

 chloric acid with the aid of heat till no more sulphu- 

 retted hydrogen is given off. The sulphides of lead, 

 antimony, and arsenic, are acted upon, but not tbe 

 tellurium, gold, or silver. Decant and wash the resi- 

 due with hydrochloric acid and hot water till the 

 impurities are removed, and the residue amounts to 

 about 38 per cent, of its original weight. This puri- 

 fied mass is now boiled in aqua regia, which quickly 

 dissolves the tellurium and gold. "When the portion 

 remaining undissolved is white, and found on trial 

 to be free from gold, it is well washed in water with 

 the addition of hydrochloric acid. It consists of 

 quartz-sand, chlorides of silver and lead, and oxy- 

 chloride of antimony with a little tellurous acid which 

 it would require a large excess of hydrochloric acid 

 to remove. From the solution the gold is first pre- 

 cipitated by means of protosulphate of iron, and tnen 

 the tellurium by metallic zinc. The gold is easily 

 obtained by fusion along with borax and saltpetre. 



The white residue is covered with water, to which 

 a little hydrochloric acid is added, and a strip of me- 

 tallic zinc is placed in the liquid. Eeaction begins, 

 and, after a few days, the mass appears black, the 

 clorides being reduced. "Wash by repeated decanta- 

 tion, dry and treat the black mass with sulphuric 

 acid, which dissolves out the silver. The tellurium 

 in the residue can be easily separated out. The at- 

 tempt to separate the tellurium from its alloys with 

 gold and silver, by the action of alkalies, has proved 

 unsuccessful. 



Metallic Printing on Cloth. The late Mr. 

 Eobinson, of the Clifton Vale Print-Works, 

 Yorkshire, made successful experiments in the 

 direction of depositing reduced metals, as print- 

 ed patterns, on cotton, worsted, and other tis- 

 sues. He found that lead, tin, bismuth, and 

 copper, could be deposited in given designs in 

 a metallic state on woven fabrics, producing a 

 variety of novel and striking effects. One se- 

 rious difficulty remains to be overcome the 

 strong affinity for sulphur of all the metals 



VOL. XII. 33 A 



capable of easy reduction and deposition, ex- 

 cept gold. When exposed in thin films to tbe 

 action of the air, they are consequently easily 

 tarnished, and lose their beautiful metallic lus- 

 tre. Yial moistens tissues of cottoo, silk, etc., 

 with a solution of nitrate of silver, dries 

 slightly, and then lays upon the cloth a metal 

 plate with an engraved design in raised lines. 

 Wherever this metal touches the cloth, the sil- 

 ver is reduced in fine black metallic powder 

 which adheres -very tenaciously to the fibre, 

 and reproduces the design with great sharp- 

 ness and delicacy. The process is most suc- 

 cessful on fine, compact goods. A slight pre- 

 vious dressing or sizing is of use. The designs 

 thus produced are permanent in air, and light, 

 and are not affected by washing in water, soap- 

 lyes, or dilute acid, and alkaline liquids. They 

 are, however, of no value, as they are devoid 

 of that metallic lustre which alone is wanted. 

 Black designs, perfectly permanent, can be pro- 

 duced to satiety with much cheaper materials 

 than the nitrate of silver. 



Phosphor- Bronze. The Russian Government 

 employed Messrs. Montefiore & Kunzel, of Bel- 

 gium, some time ago, to investigate the rela- 

 tive value of the alloys of the gun-metal for 

 ordnance, in order to ascertain the results at- 

 tainable by various combinations of phospho- 

 rous in the tin and copper. The final issue was 

 the invention of "phosphor-bronze." This 

 new alloy, it is said, can be made as tough as 

 wrought-iron, while its hardness may be reg- 

 ulated to equal that of steel ; its elasticity is 

 great. It is said to be perfectly homogeneous, 

 with a fine grain and great fluidity. This pre- 

 pares the way for considerable economy, as in 

 the manufacture of revolvers. The Russian 

 Government have found the utility of phos- 

 phor-bronze in the construction of cartridge- 

 cases for small-arms, and gave an order about 

 sixteen months ago for 176,500 pounds of the 

 new alloy to be used for this purpose. The 

 Belgian Government are making rifles of phos- 

 phor-bronze. The new Comblain rifle made 

 of this material has endured a succession of 

 rounds rising from 771 grains of powder with 

 one bullet to 465 grains of powder and 15 bul- 

 lets. In air the phosphor-bronze does not tar- 

 nish, and it is alleged to resist tbe action of sea- 

 water better than any other metallic substance. 



Smelting of Manganese Ores. Mr. Hugo 

 Tamm has made an improvement in the treat- 

 ment of manganese ores, by which he obtains 

 the metal manganese, not in a pure state, but 

 in a condition analogous to that of cast-iron, 

 by the use of common materials, and at a re- 

 duced cost. He takes any crucible that will 

 stand a white heat for several hours without 

 softening, lines it with a mixture of loam and 

 plumbago made into a paste, and then intro- 

 duces the following mixture : 

 Native oxide of manganese of good | - ^Q ^^^ 



quality j ' 



Lamp-black or soot of good quality 



Green flux 635 



Oil in sufficient quantity to merely wet the mixture. 



