1871.] 345 [Greenleaf. 



tain a trace of gold. From the fact of gold existing in this isolated 

 case, and the large proportion of oxide of iron contained in the vein 

 matter of the mine, I shall look for some discoveries of gold-bearing 

 quartz veins near that locality. 



Dr. C. F. Winslow is a resident of our city, and has become inter- 

 ested in the bismuth mine with us ; he was here this evening and 

 wishes to be remembered, and sends his kind regards. 



J. B. M. 



Mr. Moses Woolson, recently from Salt Lake City, and 

 present by invitation, confirmed this account, and said he had 

 seen fine specimens of bismuth and sal ammoniac from Cotton- 

 wood Canon, where it was said a mountain of the latter sub- 

 stance existed. He had seen finer specimens of azurite in 

 that vicinity than he had ever before observed in America. 



In reply to a question of Dr. G. F. Waters, Dr. Jackson 

 said there was rich tin ore in Winslow, Me., but the mine be- 

 ing in the hands of poor and ignorant parties was not worked. 



Prof. G. F. H. Markoe exhibited some stereoscopic views 

 of the interior of the "Mammoth Cave," Kentucky, and de- 

 scribed its most interesting features. 



Prof. Shaler also spoke of this and other similar caves. 

 He had no doubt that in the region of the Kentucky cave 

 many thousand miles of subterranean passages exist, which 

 have been formed by water percolating through the limestone. 



The thanks of the Society were voted to Mr. J. G. Swan, 

 of Port Townsend, Washington Territory, and to Mr. Chas. 

 Horton, of Boston, for gifts to the Museum. 



Section of Microscopy. October 11, 1871. 



Mr. Edwin Bicknell in the chair. Ten members present. 



Mr. Greenleaf stated, in reference to the circulation in 

 Amoeba3, that he had seen the central forward current, but 



