Rocky Mountains. 115 



various directions by veins, filled principally with sulphate 

 of lime. 



We had seen among the Indians, on the preceding day, 

 quantities of salt, in large but detached crystalline fragments, 

 resembling the common coarse salt of commerce. It had evi- 

 dently been collected from some place like the one above 

 mentioned, where it had been deposited from solution in 

 water. When we inquired the particular locality, the Indians 

 pointed to the south, and said, it was found near the sources 

 of a river, rising in that direction. 



At the place of our evening encampment, we saw the red- 

 necked avoset, (Recurvirostra americand) the minute tern, 

 (Sterna minuta) and several other strand birds, which we 

 could not approach near enough to distinguish the species. 

 There is also a very evident similarity between the plants 

 found here, and many of those growing in saline soils along 

 the sea coast. We see here several species of atriplex, che- 

 nopodium, salsola, kochia, and anabasis, all delighting in a 

 saline soil, and affording on analysis a greater proportion of 

 soda, than most inland plants. 



The day had been unusually warm. During all our mid- 

 day halt, protracted on account of the sultriness of the wea- 

 ther, to an unaccustomed length, the mercury had remained 

 at 100°, the thermometer being suspended in the closest 

 shade we could find. It is to be remarked, however, that in 

 almost every one of the numerous instances, when the mer- 

 curial column had indicated so high a temperature, a fair 

 exposure could not be had. We often found it necessary to 

 halt upon the open plain, where the intensity of light and heat 

 were. much increased by the reflection of the sun's rays from 

 the sand. The temperature indicated by the thermometer 

 suspended in the imperfect shade of our tent, or of a small 

 tree, was, however, somewhat lower than that to which our bo- 

 dies were exposed, and it will be believed, our sufferings from 

 this source were great, both on our marches and Vhile en- 



