62 ^^6 American (ieolvijisi. July, 1896 
offered for it an interpretation which, together with the presence of the 
presumably glacial pebbles in the deeply canyoned lavas, appeared to 
warrant the inference that glaciation here had a beginning coincident 
with the erection of the Sierra Nevada into a high range. 
W. F. MoKsELL, U. S. Geol. Survey. 
At the 50th meeting of this society held in Washington, D. 
C., May 27, the last meeting until next fall, papers were read 
as follows : 
The Structure and Textvrc of Soils. Under this title Prof. Milton 
Whitney, of the U. S. Department of Agriculture said : — The following- 
forces are usually spoken of as the principal ones in the disintegration 
of rocks and the formation of soils. 1. Changes of temperature. 2. 
Moving water or ice. 3. Influence of vegetable or animal life (shades 
the land ; admits air : solvent action of the roots ; chemical action of 
decaying organic matter, earth-worms, and bacteria). 4. Chemical 
action of air and water. 5. Oxidation and hydration. Attention was 
called to the fact that all of these forces, except the solvent action of 
water and hydration, are largely superficial and would not act at any 
considerable depth. They certainly can not explain the disintegration 
of rocks to a depth of 50 or 75 feet as is seen in the crystalline areas at 
the South. It is an interesting fact that soils contain on an average 
about 50 per cent, by volume of interstitial space. If the solvent action 
of water has been the main cause of the disintegration of rocks, then 50 
per cent, of the rock must have been dissolved and carried away. If the 
rock has been split up by mechanical means into the minute grains of 
sand and clay then the resulting material must have swelled to twice 
its original volume. Lantern slides were exhibited showing the shape 
of soil gi-ains and the relative size and surface area. These were used 
to illustrate some of the physical properties of sand and clay. Slides 
were also shown illustrating the texture of soils and the economical 
importance of this subject in the distribution of crops was pointed out, 
the texture of soils adapted to many of the principal crops being shown. 
By the structure of soils is meant the arrangement of the soil grains. 
This has an important geological bearing and a very important economic 
side. Slides were used to show grains of soil unflocculated as they 
exist in a jjuddled clay and flocculated as they exist in a loam soil. The 
effect of this on the relation of soils to rain fall was explained and the 
economic importance of the difference in the conditions maintained by 
the soils owing to the difference in the structure was pointed out. 
Topographic. Nomenclature of Spanish Avierica. Mr. Robert T. Hill 
of the U. S. Geological Survey, read a comprehensive paper upon the 
names given by the Spanish people to the topographic features of the 
United States, accompanying each kind by a definition and appropriate 
lantern illustration. It was held that with one or two exceptions Span- 
ish words could be found upon the published maps for nearly all topo- 
graphic forms. Over fifty of these terms were defined and illustrated, 
and Mr. Hill proposed that many of them be adopted into the English 
language, and used for forms for which the latter possesses no appro- 
priate term. The paper will be published in full. 
W. F. MoRSELL, U. S. Geol. Survey. 
New York Academy of Sciences. 
May 18th, 1896. The Academy met with president Steven- 
son in the chair. The section of Geology and Mineralogy at 
once organized. The first paper of the evening was by Mr. 
Heinrich Ries, entitled "Notes of a Trip through the Marble 
quarries of western NeM' J^ngland and eastern New York.*' 
Mr. Ries sketched out the geology and geographic distribution of 
imestone quarries along the Hudson and Lake Champlain valleys, pass- 
