CHAPTER IV. 
A DECADE OF WORK AT HOME. 
1840-1850. 
On Dr. Gray’s return from Europe, the University 
of Michigan not yet needing his services, he settled 
in New York to work on the “Flora of North 
America.” ! 
In 1841 he made his first journey to the mountains 
of North Carolina, of which he wrote an account in the 
“American Journal of Science ” in the form of a 
letter to Sir William Hooker. 
The country west of the Mississippi was just now 
opened to exploration, and for some years continued 
to afford an immense amount of new material to the 
botanist. Dr. Gray, and his friends Dr. Torrey and 
Dr. Engelmann especially, interested themselves in 
sending collectors with the various expeditions, ex- 
plorations, boundary surveys, etc., and were kept very 
hard at work in studying and distributing the several 
collections as they came in. The difficulties of com- 
munication were great, postage was very dear, and 
the post-office rule that sheets, no matter of what 
size, could be sent as one letter, while the addition of 
1A Flora of North America; containing abridged — of 
Do 
and Asa Gray. New York. Svo; vol. i., 1838-1 840, pp. xvi, 711; 
vol. ii., 1841-1843, pp. 504. 
