GEOLOGY AND MINERALOGY. 75 



As commonly known, steel is a combination of carbon and iron, made by beating 

 flat bars of pure iron, in combination -with charcoal. The carbon is first con- 

 verted into oxide of carbon, and then unites with the iron as carburet. The result 

 of this process is known as blistered steel, from the bubbles generated by gases 

 upon its surface. Shear steel consists of parallel plates of pure iron and steel, 

 welded by folding and uniting the bars of blistered steel. Cast steel is fused in 

 pots of the most refractory material, and differs from cast iron which likewise 

 contains carbon, in this respect, that cast iron is a mixture of coarsely aggregated 

 matters, graphite aud iron, whilst cast steel is a chemical combination of carbon 

 and iron. 



From the researches of Berthier, it is known that manganese will form an alloy 

 with iron. When iron is mingled with a considerable portion of manganese, 

 a brittle compound results ; but when combined with a very small proportion of 

 manganese, a steel of very fine quality is obtained, which has this advantage over 

 carbon steel : carbon steel becomes coarse when tempered in thick masses, from 

 segregation of the particles of carbon ; but no such trouble arises with magnesian 

 steel. Parties in England have lately introduced excellent wire for piano-forte 

 strings, made of this kiud of steel, as well as for cutting instruments, and other 

 purposes. In the wire, Dr. Jackson has found 1.12 per cent, of manganese, and has 

 established the fact that it resists, to a very remarkable degree, the action of 

 hydrochloric acid. Sixteen years since, Franklinite iron was manufactured by 

 Mr. Osborn into very hard and fine steel. This steel required tempering at 

 a lower heat than carbon steel. Many of our manganesian irons might be manu- 

 factured into steel, by the simple process of fusion, and a steel of uniform charac- 

 ter might be made without previous cementation with carbon. 



Dr. Jackson explained the reduction of iron in blast and reverberatory furnaces. 

 Manganesian iron ore is reduced to pure iron, or "comes to nature," in the lan- 

 guage of the workmen, with much greater rapidity than carbon iron ; hence the 

 two metals are often mixed to "come to nature" at a good time, requiring less 

 care and watchfulness on the part of the workman. Manganesian iron makes the 

 best bar iron. 



PHYSIOLOGY AND NATURAL HISTORY. 



FREAKS OP NATURE. 



The following singular illustration of the tendency of wild animals, when domes- 

 icated, to change their uniform natural color, is exhibited in a way both curiou3 

 and unusual. A writer in the "Scottish Press" says: — Mr. Souter, of Boxgrove, 

 has a game fowl which, four years since, was perfectly black, the second year it 

 was brown, the third white, and at the present time it is speckled black and white. 



Though more in accordance with ordinary operations of nature, the following 

 example of animals changing their color with the season of the year, is interesting 

 as occurring in our own vicinity. The Rev. Thomas Schreiber remarks in a note 

 to the Editor : — Is the following circumstance a freak of nature, or is it a happy 

 dispensation of Providence, mindful for every contingency to provide for the safety 

 of the animal creation ? Last summer several rabbits, black and grey in color, 

 were turned out on the grounds about the Homcwood, Toronto ; during the autumn 

 their progeny were of the same color : since the snow has covered the ground 

 two litters have shewn themselves, one litter of seven completely s7tow while, the 



