39 i TRANSACTIONS OF THE AMERICAN INSTITUTE. 



races invariably carrv their faith and knowlcdg-e with thei^i, so they like* 

 wise leave it behind them, in the fur off reg'ions they explore for the benefit 

 of the benighted inhabitants who would otherwise die perhaps in ignorance 

 of a great Creator, Christianity and its consequent civilization in all its 

 various phases of Coninierce, Trades and Agriculture. The Fur traders 

 may therefore be classed among the chief pioneers of civilization. 



Mr. Xieman stated that he had an improved process for combining felt 

 "with cloth. 



After selecting " The Manufacture of Straw Goods '' as the subject of 

 the next discussion, the Association adjourned to Nov. lOlli. 



Americ.w Ixstitvte PoLYtecbxic Association, \ 

 November 10, lS84. j 



Chairman, Prof. S, D, Tillman ; Secretary, Mr. B. Garvey. 



Calcareous Spar. 



Dr. D. D. Parmelee presented to the Institute two very lai-ge specimens 

 of calcareous spar, and on exhibiting them to the members of the Polytech- 

 nic, made the following observations : 



First specimen of Carbonate of Calcium, known as Iceland Spar, or Cal- 

 careous Spar, from Franklin, Xew Jersey. 



Second specimen from near Mount Hecla, Iceland, recently brought here, 

 a week ago, with a number of other specimens, by an American captain. 



Specimens sufficiently clear for NichoVs pi'i.vns are quite valuable. The 

 sample is a good one for this purpose. The former it will be observed is 

 comparativelv quite murky and its fibrous character qflite marked. 



The small Nichors p?'i's»)is are worth about 65 each — a half cubic inch in 

 size. Others, clearer, are worth as much as §25 each. 



A Hamburg merchant, about ten years since, hearing of the great value - 

 of Iceland Spar, was induced to import a whole ship load, but on its arri- 

 val it was found to be a murky lot, not only, but it was in a finely crushed 

 state, and had been so exposed to the heat of the volcano that it was use- 

 ful only as a caustic lime. 



The composition of this spar, it will be remembered, is lime 56.15, car- 

 bonic acid 43. T. 



The colored varieties contain traces of iron, silica, magnesia, alumina, 

 bitumen, etc. 



Fine transparent rhombohedrons, of two inches or m.ore in each of their 

 dimensions, have befen found at Oxbow, St. Lawrence Co., X. Y., in con- 

 nection with veins of lead. 



Calcareous Spar is the principal source of our polished marble. 



A peculiar fine grained, compact variety is employed in lithography. 

 The best for this purpose occurs at Papperheim and Sohlemhofer, in Bavaria. 



Artificial Leg. 

 Mr. Joshua Monroe exhibited several models of his invention recently 

 patented. Its principal novelty ie the material from which it is manufac- 



