2 62 PIONEERS OF SCIENCE IN AMERICA. 



from west to east. This hypothesis was verified in 1852 by 

 Captain McClure's making the passage in the direction 

 named. 



As Mr. Lea advanced in his geological studies, he found 

 that it was necessary to know something of shells. In order 

 to study their genera as described by Lamarck, he imported a 

 large collection of shells from China. He soon became inter- 

 ested in this branch of the science, and ultimately made it the 

 leading object of his researches. A collection of several 

 species of Unio, including some beautiful and rare specimens, 

 was sent to the Academy of Natural Sciences, in 1825, by 

 Major Long, of the Engineer Corps, who had obtained them 

 in dredging the channel of the Ohio River below Louisville. At 

 about the same time, Mr. Lea's brother Thomas, having engaged 

 to look after the shells in the vicinity of Cincinnati, where he 

 was living, shipped a barrel of shells of rare beauty, including 

 six new species. The description of these specimens De- 

 scription of Six New Specimens of the Genus Unio presented 

 to the American Philosophical Society in 1827, formed the first 

 of that long series of papers on the Unio and allied shells which 

 constitute the chief of Mr. Lea's works. Yet, at the time he 

 presented it, he had no thought that he should ever have 

 another word to say on the subject, for at that time no one 

 conceived the infinite variety of species of the family which 

 American waters are now known to contain. As a side result 

 of Mr. Lea's interest in the Unios may be mentioned the con- 

 version of his brother from an indifferent barreller of shells for 

 another to an enthusiastic student of land shells and botany, 

 and to be the author of a monograph on The Plants of Cin- 

 cinnati. 



Dr. Lea spent the travelling season of 1832 in Europe, 

 where the journal of his excursions is a record of successive 

 introductions to famous scientific men, and interesting conver- 

 sations with them, in which he was never the only one who re- 

 ceived information. In London he attended a meeting of the 

 Geological Society, and met most of the leading geologists of 

 Great Britain. At Oxford, he attended the second meeting of 

 the British Association, over which Dr. Buckland presided. 

 Meeting Dr. Buckland afterward in London, the conversation 

 turned upon the quantity of coal in the United States. Dr. 

 Buckland thought we had very little coal. Dr. Lea pointed 



