2 On the Mineralogy of Chester County, Penn. $c„ 



investigation continue uninterrupted, we may reasona- 

 bly expect some valuable acquisitions to result from their 

 researches. Already several valuable materials have been 

 found in abundance, Magnesite and ferruginous oxide of 

 chrome, (chromateof Iron,)* have been extensively and ad- 

 vantageously worked for epsom salt, and chrome yellow. 

 These articles, a few years since, were received exclusively 

 from England ; they are now made from the above materials of 

 equal quality as the foreign, and at a lower rate than they 

 can be imported, \vhich has eventuated in the total exclu- 

 sion of the foreign articles, and such has been the march of 

 improvement, and the advancement of science, that a cabi- 

 net of Natural Science! has been established at West 



* This mineral has been very improperly termed chromate of Iron by the 

 most respectable authors. Iron forms a very inconsiderable proportion of the min- 

 eral, and the chrome is not in the state of an acid but in that of an oxyde ; it may 

 therefore with more propriety be called a ferruginous oxide of chrome. 



■f The West Chester Cabinet of Natural Sciences was organised in 1826, and 

 is already m possession of a fine collection of minerals, and an extensive her- 

 barium, and contributions through the zeal and activity of the members are* 

 daily making to each department ; under these circumstances the institution is 

 now in a rapidly improving condition. The minerals are arranged in two de- 

 partments, one of which is devoted exclusively to the minerals of Chester 

 county, by which you may view at a glance, all the minerals which have yet 

 been discovered. The other is a general cabinet, arranged according to Professor 

 Cieavland's admirable system, and includes, besides those of the county and neigh- 

 borhood, a considerable number from various localities in America and Europe. 



Distieguished credit is due to Mr. John W. Townsend, corresponding secre- 

 tary, and to H. H. Van Amringe, A. Marshall, and Townsend Haines, Esqrs.. 

 curators, for their indefatigable zeal, indnstry, and consequent success, as 

 manifested by the present favorable condition, of this department of the cab- 

 inet; also to William Jackson, Vice President, and Mr. Joel Baily of East 

 Marlborough, for their very liberal donations. 



There are also two herbariums, containing upwards of two thousand species. 

 One is devoted exclusively, to the plants of the county, and denominated the 1 

 Chester county herbarium, which contains specimens of nearly all the known 

 indigenous plants of the county. Since the publicationof the Florula Cestrica, 

 a recent valuable work by Dr. Darlington, several species, not enumerated in the 

 catalogue of that publication, have been added to the collection. The other is de- 

 nominated the general herbarium, is arranged according to. the natural order of 

 Josseau, and contains about one thousand two hundred specimens, many of 

 which are from the United States, but the greater number have been received 

 from France and Germany, and constant additions are making to the herbarium 

 through Dr. William Darlington, President of the Institution, to whose scien- 

 tific and critical knowledge of this interesting department of natural science, 

 with his persevering industry and zeal, in arranging, collecting and exchanging 

 specimens, the cabinet is exclusively indebted for the remarkable condition of 

 its herbarium, which reflects high honor upon the institution. Dr. Darling-- 

 ton's arrangement, independently of many conveniences, affords so great facility,, 

 that a plant of any class and species may be selected, without the least difficulty 



