david weaver
1838 is listed as the start of commercial production of the hydrated form (on wikipedia). who knows how accurate that is. It also says the process was kept secret, which may have stunted availability (and there was probably also no real necessity for it given the huge selection of flours and crushed abrasives available dental production (porcelain teeth), razor polishing, cutlers, flatware polishing, optical polishing and on and on.

I checked the 1850 version of Holtzlappfel III this morning, and there is no mention of it there. There is an 1894 revised version that I also have, I'll dig out. I'm sure it's not mentioned there (well, not sure, but probably not mentioned there). I do recall that the 1894 version stated pretty much that the import of the washita stone had kind of wiped out a lot of the more popular (and varied) whetstones that were common to England and continental europe.

Also of interest in the original 1850 text is that there are mentions of products created at that time (synthetic sharpening stones and iron strop additive, etc) that were well regarded. In each case, developed for economic gain in use in a process (vs. economic gain by development of the product and sales to uneducated users).

No mention of carving tools on powered buffs, though.