MINERAL INDUSTRIES OF THE UNITED STATES FERTILIZERS. 17 
chiefly in connection with the lumbering industry in Michigan and 
Wisconsin; but the potentialities in this regard, while important to 
certain localities, are not great. 
The most productive domestic potash enterprise is the recovery 
of potash salts from some of the alkali lakes of the West, whose 
waters have been found to be relatively rich in potassium compounds. 
Jesse Lake in western Nebraska is an interesting example, because 
its potash is supposed to have been leached from the adjacent plains 
following extensive forest fires, representing a natural wood-ash ex- 
traction. Searles Lake in California has attracted considerable at- 
tention because of the reputed tonnage of potash present; its ton- 
nage is undoubtedly great, but a complex assemblage of salts is 
found, so that its development is proceeding along the lines of effect- 
ing a recovery of the several valuable products. Owens Lake, Cal.,, 
several lakes in Oregon, and a number of other somewhat similar 
sources offer potash possibilities, as does also the bitterns or mother- 
liquor residues in connection with the solar salt plants of Great Salt 
Lake and the Pacific coast. Considerable drilling exploration has 
been carried on in favorable geological horizons in Texas, Oklahoma, 
and other localities carrying strata of arid-climate origin, with the 
hope of finding potash beds in association, but while results of some 
little promise have been obtained in a few places, no significant po- 
tentialities have been demonstrated. 
The mineral alunite, a potassium aluminum sulphate, occurring in 
deposits of moderate size in Utah, is producing at a small but steady 
rate, and represents an interesting example oi a mineral now in de- 
mand which was looked upon a few years ago as worthless. 
A potash source which has attracted unusual attention of late, is 
the kelp or giant sea weed that grows in considerable abundance 
along the Pacific coast from Lower California to Alaska. This plant 
has extracted potash from the sea water to such an extent that its 
ash contains 30 per cent of this material. It would appear that if 
large areas of this weed could be harvested like a crop and efficiently 
treated, an effective industry would be the result. The plan has been 
put into more or less successful operation, at least in the areas of 
ranker growth in waters south of San Francisco, other products at 
the same time being saved; but the kelp industry, while it may be 
made permanent and important, can scarcely be expected to supply 
more than a very small part of our potash needs. 
Perhaps the most significant outgrowth of the efforts toward pot- 
ash development is the successful application of a method whereby 
a recovery is made of the dust escaping from the flues of Portland 
cement plants; this has become a commercial success at more than 
one locality and opens up the possibility, already under trial, of 
11616°— 17— Bull. 102, pt. 2 2 
