This is a formal but relaxed text covering assaying techniques for most of the substances which are mined. As the authors say: "At first our intention was to supply a description of those substances only which have a commercial value, but on consideration we have added short accounts of the rarer elements..."
The book's early chapters are wide-ranging, describing the general theory of assaying and a range of methods and reagents, with the later chapters describing analytical methods for different groups of metals and for some non-metallic substances. It includes many excellent illustrations of the scientific method, demonstrating the effects of changing the parameters of many of the assay techniques.
It was first published in 1889; this edition in 1904.
[The reader has omitted some mathematical examples, tables of data and descriptions of figures, where their inclusion would seem to over-complicate the text; and has attempted to describe many of the pieces of apparatus which are illustrated.] (Introduction by Peter Yearsley)