11 [108] 



During the past year a number of memoirs have been accepted for pub- 

 lication, and are either in the press, or are waiting the drawings to illustrate 

 them, now in the hands of the engraver. It is the duty of the secretary, 

 in accordance with the original plan of the Institution, to give a popular 

 account of these memoirs in his annual report. 



The first is a memoir by Dr. Asa Gray, professor of botany in Harvard 

 University, consisting of an account of a collection of plants made by Mr. 

 Charles Wright, in an expedition from Texas to El Paso, in the summer and 

 autumn of 1849. 



It was stated in my report for that year, that one hundred and fifty dol- 

 lars had been subscribed on the part of the Institution toward the outfit of 

 Mr. Wright, and that the plants collected by him would be submitted to 

 Dr. Gray for examination and description. The memoir now mentioned is 

 the result of this arrangement, though it also contains notices of plants 

 gathered by other collectors in adjacent regions, especially by Dr. Wislizenus 

 in the valley of the Rio Grande and Chihuahua ; and by the lamented Dr. 

 Gregg in the same district, and in the northern part of Mexico. This me- 

 moir is a good exposition of the character of the vegetation, and conse- 

 quently of the climate, of the regions traversed. 



Specimens of all the plants obtained by Mr. Wright belong to this Insti- 

 tution ; and these, with sets collected by Fendler and Lindheimer, form the 

 nucleus of an important and authentic North American herbarium. 



Another paper on botany is by Dr. John Torrey, of the college of New 

 Jersey, Princeton. It gives illustrations of the botany of California, and 

 describes a number of new and interesting plants discovered by Colonel 

 Fremont in his different explorations in that country. 



Some of the plants collected by this intrepid traveller have been described 

 in the appendix to his first and second report ; but many are still unpub- 

 lished. Of the collections made during his third expedition, no descriptions 

 have been given, except that two or three of the new plants were briefly 

 characterized by Dr. Gray, in order to secure priority of discovery. 



In the memoir presented to the Institution, Dr. Torrey has given descrip- 

 tions of a number of genera of new and remarkable plants, all collected by 

 Col. Fremont in the passes and on the sides of the Serra Nevada. With 

 regard to this publication Dr. Torrey remarks, that he had hoped that ar- 

 rangements would have been made by the government of the United States 

 for the publication of a general account of the botany of California ; but as 

 there is no immediate prospect of such a work being undertaken, this me- 

 moir, on some of the more interesting genera discovered by Col. Fremont, 

 > has been prepared lor the Smithsonian Institution. 



The drawings io illustrate this paper have been made, at the expense of 

 the institution, 1 y Mr. Isaac Sprague, of Cambridge, who, in the opinion of 

 Dr. Torrey, r;;nks among the best botanical draughtsmen of our day. 



The next ] aper presents the results of a series of observations made in 

 the years 1H 45-6-7, to determine the clip, inclination and intensity of the 

 magnetic f;irce in several parts of the United States, by John Locke, M. D., 

 professor of chemistry in the medical college of Ohio. The results presented 

 in this paper are a continuation of a series derived from observations begun 

 in 1837, and prosecuted annually for ten years. The first parts of the 

 series have been published in the transactions of the American Philosophical 

 Society, and have been incorporated by Col. Sabine, in his contributions to 

 Terrestrial Magnetism. A part of the observations given in this memoir 



