340 



ring support to secure a free current of air upward through the 

 central wick-tube. 



A simple way of making the experiment with an alcohol wick 

 is to inclose, between two glass tubes, a strip of cotton cloth or 

 thick paper, so that it may project a little beyond the upper end 

 of the tubes. When charged with alcohol and lighted, it will 

 furnish a hollow circular flame well suited for the temporary pro- 

 duction of the musical effect. 



These results favor the conclusion that Jlames of every kind are 

 capable of exciting sonorous vibrations, provided the air and com- 

 bustible vapors are brought together in such proportions as to 

 Ibrm more or less of an explosive mixture, and they therefore 

 confirm the explanation of Faraday, which refers the musical 

 sounds pi'oduced in such cases to a rapid and uniform succession 

 of small explosions. 



Dr. Henry Bryant presented a specimen of Iron Ore 

 from the State of New York, exhibiting throughout a 

 granular or oolitic structure. 



This ore Prof. Rogers described as characteristic of the Clintoii 

 or surgent rocks, and as found in unvarying geological relations 

 throughout the Appalachian belt from New York to Alabama, as 

 well as at some points in the northwestern States where these 

 rocks are developed. It usually presents itself in the form of 

 thin beds or plates, rarely more than two in number with an in- 

 terval of from 10 to 30 feet of calcareous shales. The adjoining 

 strata are, for the most part, slates and shales, charged with sul- 

 phuret of iron, and bands of shaly and slaty limestone often 

 crowded with fossils. The ore itself is made up of small roundish 

 flattened granules of a bright red color and rather soft texture, 

 and contains, interspersed in the mass, numerous casts of shells, 

 encrinal stems, and other characteristic fossils. 



It has been observed that these strata of iron ore, when fol- 

 lowed to a considerable depth below the surface, become more 

 and more calcareous, and at length, in many cases, pass into a 

 ferruginous limestone and even into a calcareous mass entirely 

 destitute of oxide of iron. As the continuity of the stratum of 

 ore with that of the limestone has been clearly proved, we are led 



