




PROCEEDINGS OF SCIENTIFIC SOCIETIES. 
AMERICAN ASSOCIATION FOR THE ADVANCEMENT OF Scrence.—¥. Tt 
RAL History SECTION. Chicago, IU., August 5-12, 1868. In his paper 
th 
it was, at least, thirty-eight feet thick, and extends over a surface Bi 
one hundred and forty-four acres, and is found in some places above) 
present sea-level. The salt was remarkably pure and free from 
though the latter occurred fifteen miles distant. 
In describing the geology of the delta, the author thought its prog 
seaward was not so much due to a deposit of sediment as to the up 
of the bottom of the Gulf. 
Professor W. P. BLAKE, of California, read an abstract of a paper “Upon 
the Gradual Desiccation of the Surface of the Western North 
America.” He called attention to some of the principal facts, leaving 
r 
tains, the Truckee, Humboldt, and Carson Lakes, give unequivocal 
s 
are horizontal, and show that there has not been any local elevation 
disturbance. Nor is it probable that any continental elevat 
of the glacial period in this region has not received 


