GEOLOGY. 23 



It ought to be known and remembered by every family, that 

 no article, which is glazed with oxide of lead, can be safely 

 used, in the preparation of food or drink, in which, acids are 

 contained; — or, in which, an acid may be produced by fermen- 

 tation. It is at the risk of health, perhaps of life, that pickles, 

 apple sauce, &c. are put into such vessels. Oils and fat ought 

 never to be put in such vessels, because, they act on the oxide 

 of lead, and endanger the lives of those who use them, in their 

 food. 



Bricks and tiles, are usually composed of common feruginous 

 clay, sometimes ground, and but seldom washed. To prevent 

 absorption of water by bricks exposed to the weather, a glaze 

 may be applied, at a trifling expense, by throwing common salt 

 into the kiln, when at its greatest heat. The ancient Egyptians 

 and Babylonians dried their bricks in the sun. 



The Hessian crucibles, are composed of a refractory clay 

 and sand, moderately fine. Others are made of old pots, or, 

 crucibles reduced to a fine powder, or, a coarse one, in the 

 place of sand, then black lead is mixed with it. 



Manufactories of fine procelain, have long been established, 

 in Saxony, and, at Sevres in France ; — at Berlin, in Prussia ; 

 at Vienna, in Austria, at Naples, and at several towns, in Eng- 

 land. They are, or have been established at Philadelphia, and 

 New York, and may soon be established in Ohio. Why the 

 manufacture of the common Liverpool ware, should not have 

 been yet established in America, is surprising, but, as we have 

 all the materials which enter into the composition of this ware, 

 let us hope, that the ware will soon be made here. 



It requires experience and skill, and the first manufacturer 

 may be ruined by undertaking to introduce this art, but it will 

 certainly be introduced into Ohio, before many years, we feel 

 assured. 



COAL, 



Occurs in nearly every county east of the Scioto river, in 

 our hilly region, but, is most abundant, in Gallia, Lawrence, 



