FULLERS EARTH.* 



CONTENTS. 

 Introduction. 



Definition of Fullers Earth. 



Tests for Fullers Earth. 

 Mining. 

 Drying. 



Grinding and Bolting. 

 Properties. 



Distribution in the United States. 

 Production in the United States. 



Fullers earth is a clay which has the property of absorbing 

 basic colors and removing these from' solution in animal, vege- 

 table and mineral oils, as well as from water and certain other 

 liquids. In commerce the earth finds its chief use in clarifying 

 oils, although it 'has in addition a number of minor uses, among 

 which are the removal of the excess of coloring from water in 

 dyeing cloth ; as an ingredient in talcum powders ; as a detergent 

 in fulling cloth ; and to some extent for medicinal purposes, having 

 been used in poultices for swellings, ulcers and sores. Fullers 

 earth has also been used recently in the preparation of a new 

 reagent, known as Lloyd's reagent for alkaloids. This reagent, 

 used for the removal of alkaloids from the aqueous solution of 

 their salts, is reported to be more efficient for that purpose than 

 charcoal or freshly precipitated aluminum, heretofore chiefly used 

 for that purpose. The action of the reagent is supposed to be 

 due to the presence of hydrous aluminum silicate. f 



Fullers earth, like other clays, is complex and consists not of 

 a single mineral, but of a variety of minerals, the mineral parti- 

 cles being mixed in different earths in widely differing propor- 

 tions, resulting in a varying chemical and mineralogical composi- 

 tion. The ultimate analysis does not differ materially from that 

 of other clays, although fullers earth has as a rule a rather high 

 percentage of combined water. The properties of the earth arise 



*The following paper on fullers earth is abridged from two papers pre- 

 pared during the past year by the writer. The first of these, entitled Fullers 

 Earth in the United States, was presented at the Atlanta Meeting of the 

 American Association for the Advancement of Science; the second, entitled 

 Fullers Earth Production, was prepared for Mineral Industry, 1913, Vol. xxii. 

 tjournal of the Amer. Pharmaceutical Association. May, 1914, PP- 625-630. 



