The serious prospector who decides to investigate this method of semi-qualitative analysis might want to also locate and purchase these books: Mineralogy, Crystallography and Blowpipe Analysis by Moses & Parsons (1900)
Manual of Determinative Mineralogy with an introduction on Blow-Pipe Analysis by George J. Brush (1890)
Handbook of Mineralogy, Blowpipe Analysis and Geometrical Crystallography by G. Montague Butler (1918)

I have found each of these books to contain indispensable data regarding identifying sublimates produced by the blowpipe.

Duke's Volume 1

Duke's Volume 2