EECEEATIVE SCIENCE. 



numerous sections, deplares tliat " every par- 

 ticle of its structure, and the fact that it is 

 mainly composed of carbon, proves to its 

 being a mass of vegetable matter." He pro- 

 nounces it to be a variety of cannel-coal ; 

 that it resembles other cannel-coals in its 

 geological position, in the fact that 65| per 

 cent, of it is carbon, in its burning like a 

 candle when lighted at a flame (hence the 

 original term eandle-coal, corrupted to cannel- 

 coal), and in its containing every chemical 

 ingredient found in other coals, and none but 

 such as exist in them. In other respects, as 

 colour, streak, abundance of gaseous matter, 

 it differs from other cannel-coal ; but the dif- 

 ference is in degree, and not in kind. We 

 have no space to say more on this very inte- 

 resting mineral, which has been rendered 

 so famous by the lawsuits it has occa- 

 sioned, not only in Scotland, but, we believe, 

 also in Rhenish Prussia ; and by the diffe- 

 rence of opinion which scientific men held 

 respecting it, some of whom volunteered their 

 evidence, while others were paid for it by the 

 plaintiff and defendant respectively. This 



substance is now commonly termed Torbane- 

 ite, for the sake of convenience. 



The wide difference of opinion respecting 

 it does not reflect any discredit upon ex- 

 aminations of coal under the microscope, but 

 rather shows that in this manner alone can 

 any reliable knowledge of its internal struc- 

 ture and vegetable origin be arrived at. 



Those who desire a very interesting and 

 highly useful series of microscopic objects, 

 cannot do better than learn to form good sec- 

 tions of the different coals. They are easily 

 procurable from coal-merchants, coal- wharves, 

 and mineralogists, and sections might be so 

 arranged, according to their geological ages 

 and position, as to show that there is a cer- 

 tain, though not, perhaps, a very definite rela- 

 tion between the antiquity of each kind of 

 coal and the amount of its vegetable struc- 

 ture remaining, as before observed. It is not 

 at all improbable that a careful observer 

 would discover several features of importance 

 for determining the origin and character of 

 coal, and its various deposits. 



J. R. Leifchild, A.m. 



LEAD. 



PAET II. — IN THE FUENACE. 



On presenting our letter of introduction at 

 Ballycorus, no pains is spared to make us 

 acquainted with each of the several processes 

 conducted in the various departments of the 

 works. First of all we are taken to the " ore 

 houses," where the galena, as received from 

 the mine, is stored, until it is required. 

 Previous to its reception, however, it under- 

 goes an examination, having especial re- 

 ference to the following particulars : — Firstly, 

 the quantity of water which a given weight 

 contains. This is a very necessary precau- 

 tion, as the amount of moisture mechanically 

 retained by the particles of galena is often 



very considerable. Secondly, the per centage 

 of lead. And thirdly, the per centage of silver. 

 Upon the results of this estimation the value 

 of the ore will of course depend. All these 

 operations are conducted in the assay-office, 

 to which we next pay a visit. 



The appearance of this department is not 

 that of an ordinary chemical laboratory, for 

 as all the experiments made therein resemble 

 one another in character, a much more limited 

 stock of appliances is necessary. The ap- 

 paratus consists, indeed, besides the balances, 

 of little more than a couple of furnaces ; one 

 for cupellation, the other for smelting the 



