310 



feet. A few corals are found in it, and occasionally some of tlio 

 larger cor^s. 



Mr. Daniels also presented some minute Trilobites, and other 

 fossils, from the base of the Potsdam Sandstone of Wisconsin. 

 The localities were various : the valley of the Black River, in 

 the northwestern part of the State, the mouth of Black River, 

 and a spot sixty miles up the same river. He stated that they 

 were interesting, being the oldest fossil forms yet found in this 

 country, the sandstone resting directly upon the upturned edges 

 of the Azoic rocks. Upon a small island in Black River he had 

 found perfect impressions of Crustaceans, consisting of double 

 rows of parallel tracks, precisely like those in Montreal. 



Mr. John Green — referring to a specimen of Silicious Infuso- 

 rial Earth presented to the Department of Microscopy, Novem- 

 ber 4, 1857, and which was at that time said to contain copper — 

 stated that other samples of the earth had since been analyzed 

 by Mr. Albert Gould, of the Lawrence Scientific School, with 

 the following result, viz : — 



Organic Matter and Water - . - 14.48 



Silicic Acid 82.03 



Carbonate of Lime ----- 0.32 



Oxide of Copper ----- 0.89 



Sesqui-Oxide Iron and Alumina - - 1.47 



Loss _-_---- 0.81 



100.00 



This result is the mean of two determinations. 



Mr. Gould stated that the specimens came from a pond in 

 Beddington, Maine, between ten and fifteen feet in depth, and 

 about eight or ten acres in extent. When treated with boiling 

 chlorohydric or nitric acids concentrated, no copper was found 

 by the sulphuretted hydrogen test. The same was the case with 

 diluted aqua regia. When boiled with concentrated aqua regia 

 for an hour, some copper was found; but when it was fused with 

 carbonate of soda, which certainly was itself free from copper, 

 nearly one per cent, of copper was obtained. Before the blow- 

 pipe also, on charcoal, a spangle of metallic copper was seen. 



