258 [April, 1843. 



MEETING FOR BUSINESS. 

 April 25, 1843. 



Vice President Morton in the Chair. 



The Monthly Report of the Corresponding Secretary was 

 read and adopted. / 



The Committee, consisting of Prof. Johnson, Mr. Halde- 

 man, and Mr. Peale, to whom was referred, in November, 

 1842, a communication from Peter A. Browne, Esq., accom- 

 panying some specimens of an earthy matter from Lancaster 

 county, Pennsylvania, supposed to be identical with Terra 

 di Sienna, made a report, which was adopted. The report 

 stated that after a careful investigation of the subject, and 

 comparisons in several modes with the genuine article, the 

 Committee had formed the following conclusions: 



"That the earth in question is a hydrated silicate of Alu- 

 mina tinged with variable proportions of peroxide of iron; 

 8.17 grs. of one of the best samples having been calcined at 

 redness for twenty minutes in a platinum capsule, left 6.74 

 grs. of dark brown fragments, showing a loss of 17.5 per 

 cent, of water" "and that for certain minor purposes in 

 the arts, this coloring matter may be highly useful, but as 

 a general substitute for Terra di Sienna, it cannot be 

 expected to gain the approbation of artists." 



The Committee, consisting of Mr. Cassin, Mr. Haldeman, 

 and Mr. Phillips, to whom was referred Mr. William 

 Gambel's* paper, entitled " Descriptions of some new and 

 rave Birds of the Rocky Mountains and California," reported 

 in favor of its publication, with the exception of the generic 

 and specific characters of the Eudromus variegatus of that 

 paper, which they deem it expedient .to defer until the 

 receipt of the specimen. 



* This gentleman has just completed the tour of the Rocky Mountains 

 aud California, at the instance of Mr. Kuttall, to whom this paper was 

 originally addressed, and by him referred to the Academy for Publication. 



