Blowpipe analysis - the determination of elements present in minerals by use of a blowpipe - was not taught when I was in school, but was routinely used by geologists of my dad's era. I probably missed learning this skill by only a few years: blowpipe testing was being taught during the early 1950's; it was not being taught where I went to school by the early 1970's.
A bit about the history of blowpipe analysis can be found here, here, and here. Some examples of some old, collectible blowpipe kits can be seen here, here, and through the links on this page. Blowpipe tests are still described in some rock and mineral field guides and in some mineralogy texts - for example, in Dana's Minerals and How to Study Them and in Rocks, Gems and Minerals: Revised and Updated.
For the record, the mineralogy textbook I used in school was probably this one: Dana's Manual of Mineralogy, 18th Edition by Cornelius S. Hurlbut, Jr., 1971; the one I have now is Manual of Mineralogy (after James D. Dana, 21st Edition by Cornelis Klein and Cornelius S. Hurlbut, Jr., 1993 in hardback. If you search the latter book on Amazon.com for "blowpipe tests," you will come up with erroneous results, because the search-inside feature switches to a completely different book (Manual of mineralogy, including observations on mines, rocks, reduction of ores and the applications of the science to the arts, Dana, 1855 - here's the 1876 version at Open Library), not just a different editition as it says. My 1993 edition doesn't mention blowpipes at all!
More Blowpipe Links:
Brush, G. J., and Penfield, S. L., 1906, Manual of determinative mineralogy and blowpipe analysis: Mineralogical Research Company used books with a Flame Coloration by Element table modified from The Manual at Webmineral.com
Elderhorst, W., 1861, A manual of blowpipe-analysis, and determinative mineralogy, Elderhorst: The Internet Archive
Dana, S., and Ford, W. E., 1912, Dana's manual of mineralogy for the student of elementary mineralogy, the mining engineer, the geologist, the prospector, the collector, etc: The Internet Archive
Getman, F. H., 1899, The elements of blowpipe analysis: The Internet Archive.