ELISHA MITCHELL SCIENTIFIC SOCIETY. 1/ 



ing instructions for determining the American species of the genus 

 Carex, a work wliich, though less imposing in appearance, must 

 doubtless have cost more intense application and more exact powers 

 of discriminating between specific characters than would have suf- 

 ficed for the description of many new species of plants. 



In 1824, Dr. von Schweinitz communicated to the American Jour- 

 nal of Science a short paper on the rarer plants of Easton, Pa., 

 almost all of which, he remarks, are principally met with on shady 

 rocks up the Delaware or at the mouth of the Lehigh. 



In the same year appeared his Monograph of North American 

 Carices, Being about to embark a third time for Europe this paper, 

 together with a large collection of the specimens from which it had 

 been prepared, was placed in the hands of his friend, Dr. Torrey, 

 with a desire that it might be communicated to the Lyceum of Nat- 

 ural History, and giving him full liberty to use his discretion in the 

 additions or alterations which it might, from subsequent discoveries 

 of his own, seem to demand. Finding on his return that his editor 

 had made important additions to the number of species, the honor- 

 able mind of Dr. von Schweinitz led him to request that it should' 

 appear as their joint production; remarking, that "the judicious 

 and elaborate amendments he has proposed, and the mass of new 

 and valuable matter he has added, entitle Dr. Torrey to a participa- 

 tion in the authorship of the work." This incident is mentioned 

 only as indicative of the feelings and dispositions of the man. 



The voyage undertaken this year was with a purpose similar to 

 that of 1818, and on both occasions he exercised on the delibera- 

 tions of his brethren at Herrnhut a decided and salutary influence. 



During his absence from the country his paper on the new Amer- 

 ican Species of Spheri^e, one of the largest genera among the Fungi, 

 was communicated to the Philadelphia Academy and appeared inj 

 the fifth volume of the Journal. 



On his return, near the close of the year, his pursuits, except the 

 superintendence of the literary institution, which he had previously 

 relinquished, were resumed with his wonted alacrity. The great 

 work to which he now devoted his leisure was the Synopsis of North 

 American Fungi, which was" originally designed for publication in 

 some of the European journals, but which he was induced to pre- 

 sent, in 1831, for insertion among the collections of the Philosophi- 

 cal Society of Philadelphia. 



Until the year 1830, the health of Dr. von Schweinitz had been 

 excellent, and his spirits uniformly cheerful, but the various and in- 

 creasing cares of his official station, with the sedentary employment 

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