MINERAL INDUSTRIES DIATOMACEOUS EARTH. 



27 



efficiency. The hardness, the minute size, and the shape of its grains make it 

 an excellent metal-polishing agent. 



Heretofore diatomaceous or infusorial earth has been largely used as an 

 abrasive in the form of polishing powders and scouring soaps, but of late 

 its uses have been considerably extended. Because of its porous nature it 

 has been used in the manufacture of dynamite as a holder of nitroglycerine, 

 but so far as known not in the United States. Its porosity also renders it 

 a non-conductor of heat, and this quality in connection with its lightness 

 has extended its use as an insulating packing material for safes, steam pipes, 

 and boilers, and as a fireproof building material. In this country a new 

 use of the material is reported in the manufacture of records for talking 

 machines. For this purpose it is boiled with shellac, and the resulting product 

 has the necessary hardness to give good results. 



In Europe, especially in Germany, infusorial earth has lately found ex- 

 tended application. It has been used in preparing artificial fertilizers, espe- 

 cially in the absorption of liquid manures ; in the manufacture of water 

 glass, or various cements, of glazing for tiles, of artificial stone, of ultra- 

 marine and various pigments, of aniline and alizarine colors, of paper, sealing 

 wax, fireworks, gutta-percha objects, Swedish matches, soHdified bromine, scour- 

 ing powders, papier-mache, and many other articles. There is a large and 

 steadily growing demand for it. 



Fig. 3. — Northwest shore of Lake Milton, about 5 miles south of Tavares. 



Preliminary preparation of the crude material involves drying and roast- 

 ing to destroy organic matter, if that is present. 



Production of diatomaceous earth in the United States in 1913, by States, 

 in short tons. 



State. Quantity. Value. 



California and Nevada.' 5,785 $51,556 



Connecticut, New York, and Washington 378 9,565 



Maryland, Virginia, and Florida 423 8,119 



Total 6.586 $69,240 



