No. I. From Gadsden County, Florida. U. S. Geol. Sur. 17th Ann. Rept., pt. III (cont.), page 880.

From Decatur County, Georgia. Ibid.

No. II.
No. III.
No. IV.

From Fairburn, S. D. Ibid.

Glacialite, Enid, Okla.

G. P. Merrill, Non-metallie Minerals. U. S. Nat. Mus., Rept. for 1899, p. 337, 1901.

No V. From Sumter, S. C., U. S. Geol. Surv., Min. Reso., 1901, p. 933, 1902.

No. VI. From Alexander, Ark. Branner, Amer. Inst. Min. Eng. Trans. XXVII, p. 62, 1898.

Physical Properties:-The most distinctive physical property of fuller's earth is that already mentioned, namely, the property of clarifying oils. When wet the fuller's earth is often of a lean character. This, however, is not invariable, as the Gadsden County fuller's earth is sticky when wet.

A

Test for Fuller's Earth:-Fuller's earth varies in color. It may be light buff, or brownish, or olive green or gray. It is not readily distinguished in general appearance from other clays. When dry fuller's earth adheres firmly to the tongue, but some other clays are also adhesive. practical test of fuller's earth is necessary in order to determine its value. A test may be made by the use of a glass tube to 1 inch in diameter and 2 to 3 feet long. To make the test support the tube in an erect position, the lower end being plugged with asbestos fiber. The earth is powdered and packed into the tube. Crude oils, vegetable or mineral, are then passed through it. If the clay is a fuller's earth the oils will be more or less perfectly clarified, depending upon the quality of the earth. It has been found that a fuller's earth that will clarify a vegtable oil may not affect a mineral oil, while an earth used to clarify a min. eral oil may be unsatisfactory when applied to a vegetable oil. A theory of the action of fuller's earth in clarifying oils is given by Porter as follows (U. S. Geol. Surv. Bull. 315, p. 282, 1908): "Fuller's earth has for its base a series

of hydrons almminum sillates. These lares differ in ehemical composition, but are similar in that they all Jose an amorphona colloidal structure. These colkal 8...cata preness the power of absorbing and retaining orgatle coloring matter, thus bleaching oils and fats.”

U-The Florida fuller's earth finds its chief use in fering mineral lubricating oils. According to Day,. "The common practice with these mineral oils is to dry the erh anfally, after it has been ground to 60 mesh. and run it into long cylinders, through which the crude back mineral oils are allowed to percolate very slowly. As a result the oil which comes out first is perfectly waterwhite in color, and markedly thinner than that which follows. The oil is allowed to continue percolating through the fuller's earth until the color reaches a certain maximum shade, when the process is stopped, to be continue-1 with a new portion of earth. The oil is recovered from the spent earth.* It is also used to some extent for lightening the color of cotton seed oil, and lard oil, although the English fuller's earth is better for these purposes. The original use of fuller's earth, that of cleaning, is now one of the minor uses. It is said to be used in the manufacture of some soaps. It is used in cleaning furs and by druggists as an absorbent, and recently to some extent as a carrier for insecticides.

Occurrence:-Fuller's earth occurs in stratified deposits, which, however, are often of local extent. The geological horizon in which the fuller's earth of western Florida lies has been determined by Vaughan as Upper Oligocene. The geological horizon of the deposit in Manatee County has not been determined.

Location and Extent:-Outcrops of fuller's earth have been reported at many other localities in Gadsden, Leon and Liberty Counties, and Decatur County, Georgia. It is reported to occur as a thin stratum in the Devil's Mill Hopper in Alachua County, and has been identified by the writer on the property of B. S. Quarterman, at Fairfield,

*U. S. Geol. Sur. 21st Ann. Rept. pt. 6, (cont.) p. 592. 1901.

Florida. The wide distribution of fuller's earth in north and central Florida, together with its known occurrence in south Florida, probably indicates numerous deposits not yet located.

Production of Fuller's Earth During 1907:-Three plants were engaged in mining fuller's earth during 1907. These were the Owl Commercial Co., Quincy; The Southern Fuller's Earth Co., Mt. Pleasant; and the Atlantic Refining Co., of Ellenton, Florida. The total amount of fuller's earth mined in the State during 1907 as reported to the Survey by the producers was 24,148 short tons, valued at $235,443. The product is used principally in the United States, although a certain part of the 1907 product was exported to foreign markets.

PEAT.

Peat has been mined in Florida in an experimental way for several years. Two plants are now being operated during all or a part of the year. The Orlando Water and Light Company has operated a plant near the city of Orlando for several years. The peat at this plant, after removal from the bog, is passed through a kneading machine which disintegrates the fiber and prevents reabsorption of moisture. It is then dried in the open, and after drying is cut into convenient sized pieces for local use as a fuel. Bricketting, which was formerly used, has been abandoned by this company as impracticable for this peat. The Florida Peat Fuel and Construction Company operates a plant near Bayard in St. Johns County.

Such tests of Florida peat as have been made, have been unusually promising. The fuel and gas producing value of peat from the Orlando bog was tested in the fuel and testing plant of the U. S. Geological Survey in 1906. The report on these tests contained in Bulletin 290, p. 134-135 of the United States Geological Survey is as follows:

"In connection with this test of a small quantity of

Massachusetts peat it is deemed advisable to refer briefly to a more elaborate test of peat bricks obtained from Florida, the results of which tests have been obtained in time to be mentioned here, although the test was run subsequent to the date covered by the body of the report. In the producer-gas test of the Florida peat the producer was maintained in operation for fifty hours, and no difficulty whatever was experienced either in maintaining the load or in handling the fuel bed. The peat was furnished by the Orlando Water and Light Company and was secured from a bog near the city of Orlando, Orange County, Florida.

"In starting the producer test the fuel bed was built up entirely of the Florida peat, and the usual preliminary run was conducted before the official test began. The total amount of peat consumed in the producer in the fifty-hour run was 29,250 pounds, or 585 pounds per hour. The average calorific value of the gas produced was 175 British thermal units per cubic foot. During the entire run the average electrical horsepower developed at the switchboard was 205. The amount of peat used per electrical horse power per hour available for outside purposes, including the estimated quantity required for the generation of the steam used in the operation of the producer, was 3.16 pounds, while 2.69 pounds were required per brake horsepower hour at the gas engine, available for outside purposes.

"It should be stated that the peat bricks had been dried and that the moisture content of those used averaged 21 per cent. The gas was particularly rich in hydrogen, running 18.5 per cent, and comparatively low in nitrogen (45.5 per cent).

"As there was a small supply of peat bricks left after the completion of the gas-producer tests, a short run of a little over four hours was made in the boilers. This was not sufficiently long to make any definite conclusions possible, but the results obtained were exceedingly satisfactory so far as they went. No difficulty was encountered in

keeping the boiler up to its rated capacity, and, in fact, during the four hours' run the percentage of rated horsepower of the boiler developed was 113.2. The amount of peat burned per indicated horsepower hour at the steam engine was 5.66 pounds, and per electrical horsepower huor at the switchboard was 6.98 pounds. The calorific value of the peat as used was 10,082 British thermal units per pound. The principal difficulty in the utilization of peat under boilers appears to be the frequency with which it is necessary to fire. On account of the lightness of the material and also on account of its rapid combustion the fireman was kept at work almost constantly during the test." The details of these tests are given in a later Bulletin No. 332, pp. 76-78, 1908.

The great abundance of coal in the United States has delayed the development of the peat industry. Peat deposits are known to be extensive in this country, and with the approach of the exhaustion of coal together with the advance in price as a result of increased cost of mining attention will be directed more and more to peat as a source of fuel. In Florida, in particular, the lack of a local fuel is keenly felt. If present conditions continue the supply of wood will soon be exhausted, while the importation of coal involves heavy freight charges. If the peat bogs can be drawn upon as an addition to the fuel supply the State will be greatly benefited. Some of the European countries, as is well known, have relied upon peat as a local source of fuel for many centuries. Canada, whose coal is less bountiful than that of the United States, has advanced much beyond us in the utilization of peat.

DIATOMACEOUS EARTH.

Diatomaceous or infusorial earth occurs in the State and has been mined to some extent in the vicinity of Eustis. None of this material, however, was produced during 1907.