AMERICAN INSTITUTE. 543 



Besqui-oxyde of iron, and one of sesqui-oxyde of manganese. There are 

 analyses given in many modern books, and in several quite old German 

 books. When reduced to the metallic state, there is an alloy of tin, man- 

 ganese, iron and zinc formed. What then should be the character of the 

 alloy ? The zinc being volatile, should be driven oif by the heat. Over- 

 man states that zinc can be driven off by heat alone from the galvanized 

 iron. The zinc then escapes in proportion to the amount of heat, and to 

 the length of time during which the heat is continued ; and consequently 

 two specimens would not give the same analysis, unless all the circum- 

 stances were the same. The amount of zinc, however, is always very 

 email ; its effect would be to render the metal more brittle. Considering 

 the zinc out, we have an alloy of iron and manganese. In franklinite, 

 iron is to manganese as 42 to 28. 



In the pig metal, iron is to manganese as 88 to 5. ' 



Manganese is a very oxydizable metal, consequently it is consumed by 

 exposure to heat in an open fire, and there may be a variation of from 10 

 to 20 per cent, of it in any amount of specimens. The hardness is due to 

 the manganese. Dr. Vanderweyde, last evening, showed from Berzelius, 

 that alloys of manganese and iron were long known to be very hard. At 

 a white heat the manganese is all burned out, and ordinary iron is left. 

 The burning out of the zinc and manganese is a valuable feature, for, while 

 doing so, they tuke off the sulphur and the phosphorus. Therefore, the 

 best pig metal can be made from it. I thought last evening that it could 

 not cut glass, but to-day a specimen, which I supposed contained more 

 manganese, has cut glass ; and no doubt the metal is excellent for making 

 steel. The composition of steel has been settled by Mr. Binks of England. 

 It must contain nitrogen as well as carbon. The specimen hardened by 

 Mr. Butler, seems to contain more manganese, and to differ from steel. 



Mr. Butler. — There are portions of the metal which melt easier than 

 others, so that melting away they leave a cellular structure, the walls of 

 the cells being more dense than what melted away, and being somewhat 

 different from ordinary metal. 



Dr. Stevens doubts that any sulphur or phosphorus is to be found in the 

 franklinite mineral. Judging from its geological position, the sulphur and 

 phosphorus must have been driven off by the heat which rendered the rocks 

 metamorphic. The sulphur found by analysis is most likely derived from 

 the fuel — anthracite certainly would yield it when used — and the phospho- 

 rus is from the flux. 



This mineral is found in abundance only in a very small belt of altered 

 limestone, in Sussex Co., New Jersey, while the zinc is found to extend five 

 miles as a deposit, with limestone above and below, the einc appearing 

 again in Pennsylvania. Wm. Kitchell, Esq., M. D., gives the following 

 section of the azoic rocks, showing the thickness of strata : 



6. Limestone of dark blue color, granular, silicious, calcito,. . . . 150 feet. 

 6. Limestone, bluish grey, compact, with seams of q^^.u 



