358 Steam Navigation to the Pacific, 6fc. 



As the analysis quoted gives phosphate of alumina, I applied 

 the customary test for phosphoric acid, (of fusion with carbonate 

 of soda, neutralization by acetic acid and the addition of nitrate 

 of silver,) without being able to detect any traces of this acid. I 

 conclude, therefore, that some error has been committed in stating 

 the results of Mr. Whitney's analysis. If we set down the phos- 

 phate of alumina as alumina, the constitution of the mineral 

 would not be inconsistent with that of the Haddam iolite, as de- 

 termined by Dr. Thomson. I verified the aqueous content of 

 the chlorophyllite, and in so doing observed, that the powdered 

 mineral, both before and after ignition, corresponded very exactly 

 with that of the Haddam pinite. 



By the reader of my treatise on Mineralogy, it will be observed 

 that I referred the Haddam mineral, as well as that from Lan- 

 caster, Massachusetts, and the French pinite, to the species mica. 

 I now relinquish that opinion, although I am not equally satisfied 

 that the minerals from the two last localities belong to iolite, as in 

 the case of those which form the subject of the present notice. 



New Haven, July 15, 1841, 



Art. Xn. — Steam Navigation to the Pacific hy the Isthmus of 

 Panama and along the Western Coast of South America. 



Some interesting pamphlets on the subject named in the title 

 were placed in our hands early in 1840 in Boston, by a brother of 

 Mr. William Wheelwright, to whom mainly the world is indebt- 

 ed for an undertaking which may be with propriety ranked the 

 first among the enterprises by steam. Mr. Wheelwright has la- 

 bored several years at this undertaking and is now on the eve of 

 success. From himself we have just received a communication, 

 which, although not intended for the public eye, contains many 

 facts in which the world is interested, and we therefore venture 

 to annex certain portions of his letter or abstracts from it. 



Talcahuano, March 8th, 1841. 



TO PROFESSOR SILLIMAN. 



Dear Sir — I had the honor of receiving your valued favor only 

 a day or two since, having left the United States about the time 

 it was written, to take up the superintendence of the Pacific 



