REPORT OF THE STATE GEOLOGIST. xlix 



constituents of the soil is very great, so that its action is both chemical 

 and physical. Its use is perhaps most beneficial when composted with 

 organic manures or the greensand marls. 



When the calcareous marls are soft enough to be easily powdered 

 they may be applied as they are, and in this condition the action of the 

 lime is much more gradual and of longer continuance. When they ex- 

 ist as harder rocks they will have to be burned before applying them. 



Among the rocks of the Cretaceous series are many deposits which 

 are especially adapted for use in this way. Localities are numerous in 

 the divisions known as the Austin chalk and the Washita limestone 

 which will afford a soft material well suited for the purpose. 



It often happens that in the greensand beds themselves there are 

 large deposits of fossil shells still in their original form as carbonate of 

 lime. Where these occur the marl is of great value, as it contains that 

 which will render it most valuable on such sandy lands as need it. 



CLAYS. 



Some of the Clays of East Texas will prove of value as fertilizers on 

 account of the large amount of potash they contain — as high as five and 

 six per cent in certain cases. While it is true that much of the potash 

 is in chemical combination with silica, and therefore only soluble with 

 difficulty, if composted with quicklime this substance will be rendered 

 more soluble and prepared for plant food. 



FICTILE MATERIALS. 



Texas has not yet begun to take that place among the manufacturers 

 of pottery and glassware which the character, quality and extent of the 

 materials found within her borders render possible. For pottery mak- 

 ing there exist clays adapted to every grade, from common jug ware and 

 tiling through Yellow, Eockingham, C. C, White Granite or Iron Stone 

 China, to China or Porcelain of the finest quality. Grlass sands are also 

 found of a high degree of purity, and many other materials of use or 

 necessity in the manufacture of these various grades of goods are found 

 here. 



While the subject of clays has not yet received the attention that it 

 is proposed to give it, numerous specimens have been secured and an- 

 alyzed, with the result of proving the facts as stated above. 



Among the clays of the Division known as Coast Clays are some that 

 will answer for the coarser stoneware, such as jugs, flower pots, drain 



4:— geol. 



