METALS. 



459 



lead, at a red heat 38'V, just fluid 16*7 ; for 

 zinc, high red heat lOo'O, just fluid 63'5 ; bell- 

 metal, containing 20 per cent, of tin, 159'5 and 

 117'0; gun metal, containing 10 per ceut. of 

 tin, at a high temperature, 173 - 0, pasty, 127'0; 

 brass, with 30 per cent, of zinc, at a high tem- 

 perature, lo'J'5, pasty, 119'5. The agreement 

 between the results obtained by experiment in 

 the last three cases, and those calculated from 

 the numbers given by their respective constitu- 

 ents is such that the authors conclude that the 

 total quantity of heat necessary to melt an 

 alloy, may he considered to differ very little 

 from the sum of the quantities of heat neces- 

 sary to melt its constituent parts. 



Improvement in Iron and Steel. The year 

 1861 has been remarkable for the progress 

 made in the processes of manufacture, for the 

 number of new or improved applications, and 

 for the light shed upon the true nature of iron 

 and steel. Mr. Fairbairn, in. his address as 

 President of the British Association for 1861, 

 thus sums up some of these : " A consecutive 

 series of chemical researches into the different 

 processes, from tlie calcining of the ore to the 

 production of the bar, carried on by Dr. Percy 

 and others, has led to a revolution in the manu- 

 facture of iron ; and although it is at the pres- 

 ent moment in a state of transition, it never- 

 theless requires no very great discernment to 

 perceive that steel and iron of any required te- 

 nacity will be made in the same furnace, with 

 a facility and certainty never before attained. 

 This has been effected, to some extent, by im- 

 provements in puddling; but the process of 

 Mr. Bessemer affords the highest promise of 

 certainty and perfection in the operation of 

 converting the melted pig direct into steel or 

 iron, and is likely to lead to the most important 

 developments in this manufacture. I must not, 

 however, pass over in silence the valuable light 

 which chemistry has recently thrown upon the 

 composition of iron and steel. Although Des- 

 pretz demonstrated many years ago that iron 

 would combine with nitrogen, yet it was not 

 until 1857 that Mr. C. Binks proved that nitro- 

 gen is an essential element of steel, and more 

 recently M. Caron and M. Fiemy have further 

 elucidated this subject; the former showing 

 that cyanogen, or cyanide of ammonium, is the 

 essential element which converts wrought iron 

 into steel ; the latter combining iron with ni- 

 trogen through the medium of ammonia, and 

 then converting it into steel by bringing it, at 

 the proper temperature, into contact with 

 common coal gas. There is little doubt that in 

 a few years these discoveries will enable Shef- 

 field manufacturers to replace their present un- 

 certain, cumbrous, and expensive process by a 

 method at once simple and inexpensive, and so 

 completely under control as to admit of any re- 

 quired degree of conversion being obtained 

 witli absolute certainty. Mr. Grace Calvert also 

 has proved that cast-iron contains nitrogen, and 

 has shown that it is a definite compound of 

 carbon and iron, mixed with various propor- 



tions of metallic iron, according to its nature." 

 Among the new or improved applications may 

 be enumerated the use of steel for bells, can- 

 non, railway bars, car axles, and even tor cov- 

 ering vessels, while iron has been employed on 

 a great scale for plating vessels of war, und for 

 cannon of unprecedented size. Much has also 

 been added to our knowledge of the alterations 

 to which iron is subject, when exposed to vi- 

 brating action, as in suspension bridges, loco- 

 motive axles, &c., as well as of its other physi- 

 cal properties. A report made by Mr. J. A. 

 Roebling, the engineer of the Niagara suspen- 

 sion bridge, is especially full of information on 

 these subjects, and valuable reports have also 

 been made by Fairbairn in England, Schimmel- 

 bach at Liege, and Bourville in Austria. 



Gold in Nora Scotia. A range )f clay slates 

 and quartz rocks along the southern coast, ex- 

 tending about 250 miles in length, and stretch- 

 ing inland in some places 20 to 30 miles, whose 

 geological place appears to be the lower part 

 of the Lower Silurian, and consequently about 

 the same age as the auriferous and cupriferous 

 rocks of Lower Canada, has, within the last 

 year, been found to be in many places rich in 

 gold. The first gold found was at Tangier, 40 

 miles east of Halifax, in 1860, but the quantity 

 found was small, and it was not until the spring 

 of 1861 that any discoveries of importance were 

 made. In March, 1861, a man, stooping to 

 drink at a brook near the mouth of the Tangier 

 River, saw a lump of gold among the pebbles, 

 and on searching found others. As this was in 

 a locality eminently favorable to mining opera- 

 tions, being within half a mile of navigation, a 

 considerable number of persons flocked to the 

 locality, and lots of 50 feet by 20 were leased by 

 the Government. The greatest depth reached, 

 at the time of the Hon. Mr. Howe ? s report, was 

 45 feet, and the largest nugget $300. The 

 metal is found in scales and jagged pieces in 

 quartz veins, very little having yet been ob- 

 tained by washing. The discoveries at Tangier 

 were followed by others at Musquodoboit, Lan- 

 rencetown in the vicinity of Halifax, near Lu- 

 nenburg, and at TVine Harbor, 50 miles east of 

 Tangier, over a total length of 130 miles, from 

 S. W. to X. E. ; and in all probability gold will 

 be found to pervade the rocks over the whole 

 extent of the formation. It has also been re- 

 ported from the inland districts of Eastern and 

 Middle Pictou, in quartz veins running through 

 Upper Silurian slates, but the quantity found 

 seems to have been small. Mr. O. C. Marsh 

 visited the gold region in Aug. 1861, and states 

 that, thongh the metal is mostly found in the 

 quartz veins, he noticed it in one instance in the 

 clay slate. The associated minerals are chiefly 

 mispickel and iron pyrites, the latter being it- 

 self auriferous. A few perfect crystals of gold 

 were found. Copper pyrites, galena, magnetic 

 iron, and hematite were also found in small quan- 

 tities. At Tangier about 700 men were work- 

 ing claims, but at least one-third of the gold 

 was lost by the rude methods employed. At 



