ISAAC LEA. 26l 



the historian of the Inquisition ; and Frances Lea, who died in 

 1894. Mr. Lea had inherited a strong taste for Nature from 

 his mother, and found a congenial spirit in Prof. Vanuxem, 

 then also a youth, with whom he formed the habit of making 

 collecting excursions around the city. The two companions 

 were soon led, by what they found and observed, to inquiry 

 into the composition and structure of the rocks ; they had to 

 pursue it at first without any guidance, but in a short time 

 became acquainted with the mineralogical collection of Dr. 

 Adam Seybert. A diversion to their pursuits was given by the 

 occurrence of the war with Great Britain in 1812. They joined 

 a volunteer rifle company, which offered its services to the 

 Governor. Although the company was disbanded without 

 being called into service, young Lea had, by joining it, en- 

 gaged enough in war to violate the principles of the Society of 

 Friends, and he lost his birthright in it. Among the excur- 

 sions which the two youths made was one to the coal mines 

 near Wilkesbarre, where they found slates containing mollusca, 

 which Lea described forty years afterward in the Journal of 

 the Academy of Natural Sciences. They walked back, over 

 the Pocono Mountain through the Wind Gap, where Lea found 

 the first trilobite they had ever seen, and down the Delaware 

 River. In 1815 they were both elected members of the Phila- 

 delphia Academy of Natural Sciences, and began to take active 

 parts in its proceedings ; and in this society Mr. Lea read his 

 first paper, already referred to, embodying the results of many 

 years of close observation which the friends had made upon 

 the rocks during their excursions. 



On the publication, in 1818, of Prof. Silliman's prospectus 

 of the American Journal of Science, Mr. Lea procured the names 

 of fourteen subscribers to the journal an act which Prof. Silli- 

 man afterward declared " was the turning-point of the scheme " ; 

 for, receiving such encouragement from a person with whom 

 he had no personal acquaintance, he was sure the journal 

 would be successful. Mr. Lea contributed several papers to 

 the early numbers of this journal, at the editor's request ; but 

 the article of this period which is perhaps most worthy of 

 special mention is one that he published in 1828 in the Ameri- 

 can Quarterly Review, on the Northwest Passage, in which he 

 expressed the opinion that, if the passage were ever made, it 

 must be, as was indicated by the direction of the currents, 



