Part,  Chapter

1 1,5| other a pyrite, also called sulphuret of iron. It was, therefore
2 1,7|   coal, flint, alumina, and sulphuret of iron-the latter in excess-it
3 1,7|   necessary to separate the sulphuret of iron, and transform it
4 1,7|  ten or twelve days for the sulphuret of iron to be changed to
5 1,7|   the transformation of the sulphuret into sulphate of iron had