218 Dr Colquhoun on the Argillaceous Ore of Iron 



easy to conceive how the most important of the ores of iron 

 should have attracted so Httle regard among men of science. 

 For there seems to be scarcely any branch of art, to which the 

 metallurgic products of this ore are not either immediately or 

 remotely essential. In almost every mechanical trade, iron 

 forms the tools, without which the labourer might forsake his 

 craft; and in all our manufactories, where the power of a 

 thousand hands is condensed within a few pieces of machi- 

 nery, the want of iron would paralyze the enterprise of the 

 merchant. 



In the following memoir it is proposed to give a connected 

 view of the nature and history of the argillaceous carbonate of 

 iron, and of the principles and practice of the metallurgic art, 

 as far as relates to the manufacture of this metal. And as 

 such a course of investigation evidently embraces a variety of 

 subjects, each of which, in order to be fully elucidated, will 

 require to be discussed with considerable minuteness of detail, 

 we shall find it convenient to divide the memoir into several 

 distinct parts. The first of these will be devoted to an ex- 

 amination of the composition of the crude materials employed 

 in the manufacture of iron, and will comprise a short account 

 of the various opinions which have been entertained respecting 

 the ore of iron in the progress of modern chemistry. 



Part I. — Description and History of the Crude Materials 

 employed in the mamufacture of Iron. 



These materials may be conveniently divided into two classes; 

 first, the ore of iron ; second, the fuel and fluxes which are ap- 

 plied in order to separate the metal from the ore. We shall 

 consider them separately in corresponding sections of this first 

 part of the memoir. 



Section 1. — On the Argillaceous Carbonate of Iron. 



This ore is a chemical compound of the protoxide of iron 

 and carbonic acid, and is the source from which almost the 

 whole of the iron manufactured in Britain is extracted. 



The history of the ore from its first appearance in the works 

 of mineralogists, down to the period when its true properties 

 were accurately discriminated, and its just place assigned to 

 it in the mineral kingdom, is not without interest. As it is 



