Proceedings of tee P olytecekic Association. 705 



Ikon. 



Attention was next directed to the reading by Dr. Feiichtwanger, 

 of a paper on iron, in which he spoke briefly of the liistory of this 

 metal as used among the ancient peoples of the earth, and mentioned 

 its wide diffusion in the mineral, vegetable and animal kingdoms, and 

 in the meteorites supposed to be splintered from other planetary 

 bodies. He then proceeded to a consideration of several of the 200 

 different varieties of iron ore, one of the principal of which is the 

 magnetic or bog iron ore, containing about seventy per cent of the 

 metal, and from which the iron of New Jersey and Pennsylvania is 

 made ; as next to this was mentioned the Franklinite, which, in addi- 

 tion to its iron, contains about sixteen per cent of manganese, and is 

 used in the iron manufacture a.s an equivalent or substitute for the 

 German spiegeleisen. The speaker also spoke in a few words of the 

 red oxyd or hematite, which contains about seventy per cent of iron, 

 and is employed in the production of much of the iron made in the 

 State of ISTew York, and treated of various other kinds with reference 

 to their special adaptation not only in tlie manufacture of iron, but 

 of steel. The clirome iVon ore is of an iron-black color, and contains 

 about sixty per cent of chromic acid and twenty per cent of iron. 

 This mineral was stated to be abundant in the United States, especi- 

 ally in Mar/iand, Pennsylvania and California. 



Iron pyrites which contain fifty-three per cent of iron and forty- 

 seven sulphur, cannot be employed in the production of iron of good 

 quality, owing to the impracticability of wholly extracting the sul- 

 phur, but is largely used in the manufacture of sulphuric acid and 

 copperas, and also to a great extent by dyers in making a black dye. 



Mispickel is an arsenical pyrites, very abundant in Cornwall and 

 Saxony, and largely employed in the production of arsenic. In the. 

 mines of i!^ova Scotia this mineral has gold associated therewith. 



Lignite m New Jersey. 



Dr. Jolm F. Boynton, of Syracuse, said he had just returned from 

 an examination of lignite, near Keyport, N. J. Perhaps some por- 

 tions of these lignites are diffused still higher, and belong to- the 

 tertiary period. He took some of these specimens for examination, 

 which were found about twenty feet deep ; they were some four feet 

 four inches long. Two tons of it w^ere sent to a manufacturing firm- 

 in Water street, in this city, and they were using it in furnaces for 

 driving their machinery. It burns very freely and with cons-iderable^ 



[Inst.] 45 



