542 TRANSACTIONS OF THE 



3(1. Degree of hardness of the metal, and circumstances which render it 

 " hard," " harder," and "hardest." 



4th. Tenacity of the wrought iron. 



5th. Capability of conversion into steel. 



Further, he suggested the appointment of a committee, to make out a 

 full report of all the facts elicited by the Club on this topic. 



Dr. Deck would strive to find time to analyze the metal, if another 

 chemist be appointed with him. 



The Chairman read the following letter : 



New York, January 6, 1860. 



Prof. Mason, Pres. Polytechnic Society : Sir — Learning that one of 

 the subjects of discussion before your Society is franklinite, I have taken 

 the liberty to send you a specimen of the franklinite pig iron, produced at 

 the works of the New Jersey Ziuc Co. This iron is designated by metal- 

 lurgists as S-pecular Iron. It is remarked for its very white, silvery 

 lustre, and the very large crystaline facets, and its foliated or lamellar 

 structure. It is extremely dense, having a specific gravity of 7.G9, being 

 from 10 to 12 per cent, greater than ordinary iron. A remarkable feature 

 of this iron is, that the large crystals and facets are not attracted by the 

 magnet. 



A very careful analysis of this iron gives — iron, 88.30 ; carbon, chera- 

 i-eally combined. 5.48; carbon, free or graphite, 0.00; manganese, 4.50 ; 

 siiicium, 0.20; sulphur, 0.08; phosphorus, 0.15 ; zinc, 0,30; loss, 0.99= 

 100. 



It is proper to state that this iron by itself, from its extreme hardness, 

 is not suitable for castings. It is chiefly employed for conversion into 

 bar iron — a specimen of which is herewith presented. The aspect of the 

 fracture shows it to be a bundle of fibres. 



A careful test of the iron in the hydraulic press, of a bar one inch square, 

 required a weight equal to 77,000 lbs. per square inch, to tear it asunder. 

 This shows it to be equal to the very best iron known to commerce, 



I am pleased to know that this subject has presented itself to your 

 Society ; and I trust the discussion will do much to discover many valuable 

 properties in this iron yet unknown. In this hope, I am sir, 

 Most respectfully, your obdt, servt. 



HENRY AITKEN, 



Prest. iV. /. Zinc Co. 



Dr. Deck thought an analysis would give more phosphorus, probably 

 owing to oyster shells being used as a flux. 



Mr. Seely has before seen the analysis given in the letter, under the 

 names of Drs. Dickinson and Jackson, and thinks it reliable, but no one 

 ' analysis can determine anything about the matter, for the nature of the 

 compounds will give different results under different circumstances. The 

 mineral is a definite chemical compoui; l is definite and as pure as water, 

 containing oxyde of iron, oxyde of manganese, and oxyde of ziuc. Frank- 

 linite is composed of one atom of oxyde of iron, one of oxide of zinc, one of 



