9J: 



MISCELLANEOUS INTELLIGENCE. 



[1854. 



ExTR.\CTioN OF Metals BY THE BATTERY. — Bunscn has been investi- 

 gating the circumstances most favorable to the separation of metals 

 from tlieir compounds. These are the density of the current, and the 

 greater or less concentration of the liquid to be decomposed. The 

 greatest effect is obtained with the most dense current and the most 

 concentrated solutions. Density denotes tlie concentration of electric 

 action ujion a single point, analogous to the concentration of heat and 

 light in the focus of a concave mirror. Tims, ive connect a cliarcoal 

 crucible with the positive pole of the battery, and place in it a small 

 capsule of glazed porcelain containing the liquid to be decomposed. The 

 space between the capsule and crucible is then fiUtid with hydrochloric 

 acid, and the liquid in the small capsule is put in communication with the 

 battery by means of a thin platinum wire, which must be exactly in 

 the centre. The current is then established between a large surface, 

 the charcoal crucible, and a fine platinum wire in which it is concen- 

 trated, and the current becomes capable of overcoming affinities 

 which have resisted powerful batteries. The whole apparatus is then 

 set in a large porcelain crucible, and kept warm in the sand-bath. 

 Chrome and manganese are thus readily separated from the solution of 

 their chlorides, provided the negative pole is .imall and the solution 

 very concentrated. In this state the chrome is quite pure ; it presents 

 the appearance of iron, but is less affected by moist air. Heated in 

 the air, it is converted into sesqui-oxide. It resists nitric acid even 

 when boiling, but is acted on by hydrochloric and dilute sulphuric 

 acids, forming proto salts. Its density coincides with the density cal- 

 culated from the atomic volume, Bunsen obtained sheets of chromium 

 of more than 50 square millimetres surface ; they were brittle, and 

 showed a perfect polish on the side which had been in contact with the 

 platinum. jManganese was obtained in the same manner in very little 

 plates of more than 100 square millimetres surface, which oxidised in 

 damp air almost as rapidly as potassium. To induce barium and cal- 

 cium, a denser current was required. Concentrated solutions of the chlo- 

 rides are acidulated with hych-ochloric acid, and poured boiling into 

 the glazed porcelain capsule. Amalgamated platinum wire in connec- 

 tion with tire battery is then introduced, upon which calcium is depo- 

 sited in a grey layer, easily detached, and containing a little mercury. 

 If water or moist air be present, this amalgam is r.apidly oxdised with 

 evolution of hydrogen ; when heated it burns with brilliancy. Barium 

 is more easily extracted. The chloride is powdered and made into a 

 paste with water acidulated with hydrochloric acid, heated to 200° 

 Fah. in the water-bath, and the current established. The amalagam 

 of barium thus obtained is silvery white, and very crystalline. In 

 contact with moist air, it is converted into hydrate of baryta. If heat- 

 ed in a current of hydrogen upon a charcoal support, the mercury is 

 carried off, and a residue of porous barium appears, containing brilliant 

 metallic particles. 



CoxscMPTioN OF Coal in the United St.ates. — The Consumption 

 of coal does not increase so rapidly as was supposed. In 18.52 the 

 increase was less than 13 per cent., and left a surplus in the marliet. 

 In 1853 the increased supply was less than 9 per cent, from all 

 sources. To this, of course, is to be attributed the high price of coal 

 during the latter part of the year; but taking tlie average over 12 per 

 cent, it will reach it. - We see no good reason to believe that this 

 average per ceutage in the demand is likely to be exceeded in the pres- 

 ent year, which would require an increase in the supply of about 

 623,000 tons in 1854, from all sources, to keep the market healthy. 

 The increased supply can easily be furnished by the different regions, 

 provided dealers and customers will come forward and take coal 

 early in the spring. The following is a summary of operations in 

 Schuylkill county : — 



Total number of collieries. ..113 



Red ash collieries 58 



■\Vliite ash collieries 55 



Whole capital invested in these collieries 

 By individual operators, about 



Number of opei'ators 82 



Employed at collieries 9792 



Miner's houses out of towns 2756 

 $3,462,000 

 2,600,000 



Thickest vein worked at Hecksherville 80 ft. 



Smallest 2 ft. 



All the coal lands now worked in Schuylldll county are owned by 

 six corporations, and about 60 individuals. About 25 of the owners 

 reside in Schuylkill county, and the balance abroad. The coal rent 

 will average 30 c. a ton. The product of 1853 in Schuylkill county was 

 2,551,003 tons. This would give an income of §765,480 to the land- 

 holders in the shape of rents for the year. — Fostville Mining Journal. 



Ox THE Permanent Expansion of Cast Iron by successive Heat- 

 ings. — In the Jlemoirs of the Industrial Society of Hanover for last 

 year, there are some interesting remarks on tliis question. The re- 



markable phenomenon that cast-iron presents on being heated, of not 

 returning back to its original volume, but of continually showing an 

 increase of the volume, and of permanently acquiring an enlarged 

 volume by successive heatings and coolings, had been first observed 

 by Rinsep, in 1820. That chemist found that a cast-iron retort, 

 whose capacity was exactly measured by the quantity of mercury 

 which it could contain, held at firet, 9-13 cubic inches; after the first 

 heating and cooling, 9-64 inches; and after three heatings, up to the 

 melting point of silver, 10-1 6 cubic inches, The cubical expansion 

 ought, therefore, to be 11-28 per cent., which gives 3.76 per cent, nearly 

 of linear expansion. 



At subsequent periods different phenomena were obsei-ved, more or 

 less confirmatory of this law. The cast-iron bars of grates, where 

 powerful fires were made, were frequently observed to elongate, so 

 as to become jammed tight in their frames; and when these obstructed 

 all further enlargements, the bars become curved or twisted. Mr. Brix, 

 in his work on the calorific power of the fuels of Prussia, has detailed 

 a few experiments on this subject. By the aid of several measurements, 

 he has shown that the entire permanent elongation increases after each 

 successive heating, but that the amount produced by each heating 

 diminishes the more frequently the bar is lieated, until it finally be- 

 comes insensible. Thus, a furnace bar 3J feet long, after being three 

 days exposed to a moderate fire, had already acquired a permanent 

 elongation of 3-16ths of an inch, or -446 per cent.; at the end of seven- 

 teen days, 1-042 per cent.; and after thirty days, 2 per cent., but had 

 not yet reached its maximum. Another bar of the same kind, after a 

 long sex'vice, had a permanent elongation of 3 per cent. 



If it be remembered that bars while exposed to the fire undergo 

 another temporary elongation, we must agree with M. Brix, that an 

 allowance should be made in a bar whicli has not as yet been used, 

 amounting to 4 per cent, of its length, for this cause of elongation. 

 The bars must, of course, be sufiiciently long to stand between their 

 supports when cool; but it seems that hitherto sufficient room has not 

 been given for this permanent expansion in laying down new bars. 



Robinson's Patent for the Novel Application of the Slags 



OR ReFI'SE M-ATTEES obtained during the M.tNUFACTUEE OF MeTALS. 



— Dr. George Robinson, of Newcastle-on-Tyne, has taken out a patent 

 for the formation of sheets or plates from the slags produced in the 

 various processes of manufacturing and refining iron and other 

 metals. He proposes to convert the molten slag into sheets by pour- 

 ing it upon an iron or other table previously heated, and then rolling 

 or pressing it to any requisite thickness, according to the purpose for 

 which it is intended to be used. The plates thus formed are afterwards 

 to be annealed, by being allowed to cool gradually in any suitable 

 furnace. While in a plastic state, the sheets may be ornamented by 

 means of suitable elevations and depressions on the rollers by which 

 they are formed. When cold the thin sheets of slag may be used for 

 roofing instead of slates, the thicker plates for flooring, and those 

 having patterns on their surface for covering walls. The Newcastle 

 papers, in alluding to the invention, state that in that district alone 

 there are materials for a very extensive manufacture, and in the 

 other great seats of metalliu'gic operations the supply of suitable slags 

 is practically unlimited. 



Tre Precious Metals in England. — At a time when the exti-action 

 of gold in England occupies so much attention, the following account 

 of the presence of silver in England may prove interesting. An im- 

 mense silver mine was worked in the vicinity of Aberystwith, in the 

 reign of Elizabeth, by which a Company of Germans enriched them- 

 selves ; after whom Sii' Hugh Middleton accumulated £2,000 a month 

 out of one silver mine at Bwlch-yr-Eskir, by which produce he was 

 enabled to defray the expense of bringing the New River to London. 

 After him, Mr. Bushell, a servant of Sir Francis Bacon, gained from 

 the same mine such immense profits, as to be able to present Charles 

 I, with a regiment of horse, and to provide clothes for his whole army. 

 Besides this he advanced, as a loan to his iMajesty, no less a sum than 

 £40,000, equal to at least four times the amount of the present 

 currency ; and he also raised a regiment amongst his miners at his 

 own charge. 



RosiN Oil for lubricating IMaciiinery. — Payen and Buran re- 

 commend the oil obtained by the distillation of common rosin with 

 from 5 to 10 per cent of quicklime, as a good material for greasing 

 machinery. As it is generally slightly acid, even when distilled with 

 lime, it is recommended to add from 2 to 5 per cent, of lime or magnesia 

 to the cold oil, which unites with the free acid, and gives the whole mass 

 the consistence of butter. — Polytechnisches Centralblatt, Ko. 12, 1853. 



