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7 
Reconnoissance in New Mexico.—Johnson., 85 
for salt in such a way as to explain the above phenomenon, 
while the concentration from a normal saturated solution is an 
element to be considered. On the surface.of the lake float 
thin particles or scales of salt, and from the top of the sur- 
rounding ridge the appearance is that of a deep basin, the 
bottom covered with snow. At the bottom of the lake is a 
thick deposit of pure crystalline salt, the cubical crystals being 
very large and well preserved. The salt is secured by driving 
well out into the lake and loading the wagon from the rich de- 
posits on the lake bottom. About the shores of the lake is a 
thick crust of the salt, but of little value compared to the purer 
product in the deeper portions. Clay from two feet below the 
surface shows 7.1% salt. The subsoils from the different lake 
basins are rather constant in character, there usually being 
from one to one and a half feet of yellowish clayey mud, (often 
containing one or more gypsum bands), underlaid by a rather 
pure clay varying from dark slate to almost white in color. 
The so-called alkali ponds further south resemble the salt 
lakes to the north in size and appearance, and are frequently 
dry and covered with a white incrustation. That these ponds 
are essentially saline is evident, for when one tastes the water 
or the white crust one is first impressed by the strong saline 
taste; and not until a few seconds later does the disagreeable 
alkaline taste become noticeable. Water from one of these 
ponds shows 26.1% salt. The surface incrustation from an- 
other yields 20.5% salt, the remainder being largely sodium 
sulphate. 
Still further south are other salt lakes similar to those at 
the north of the basin. Chico lake is rather round in shape, 
perhaps a third of a mile across, and was dry at the time of 
our visit. The whole southern end was merely a broad mud 
flat, but the northern portion was covered by a very thin salt 
crust, on which were scattered beautiful large cubes of sodium 
chloride. On removing this thin crust considerable soil ad- 
hered; analysis of the whole showed 57.5% salt. Soil from two 
feet below the surface shows 12.5%. Under the usual layer of 
a foot and a half of yellowish mud comes about six inches of 
thin layers of dark greenish soil alternating with thin layers 
of salt. Below this is dark slate-colored clay. What appeared 
to be the impressions of grass were found in both the green- 
