Jim McK., I'm happy to oblige. What we are seeing here is cultural (not to mention scientific) lag. Using "potash" in place of the proper name for the element, potassium, is left over from the 18th century. Which seems to be about where some horticulturists and all gardening magazines still reside. (Ouch!) The terms "sulphate of potash" and "muriate of potash" are simply archaic names for potassium sulfate and potassium chloride. There is no "potash" (K2O) hidden in the sulfate. Personally, I have a heck of a time figuring out what the N-P-K numbers ought to be for chemicals like potassium nitrate, ammonium phosphate, etc. When I mix my own from lab chemicals, I end up with the metric numbers, not the silly American fictions. You can tell the difference between cheap and premium fertilizers by reading that fine print. If they use potassium chloride (KCl) as the source of potassium, it's cheap stuff. If they use sodium phosphate, it is even worse quality (and even cheaper). Jim, I'll go off on a tangential rant if I don't quit now! If you have any more questions, drop me a note later. Best to all, Jim Shields ranting and raving in central Indiana (USA) over the scientific illiteracy of certain parts of the world At 06:32 PM 5/7/2008 -0400, you wrote: >Jim Shields, if you don't mind, let's continue the inorganic chemistry >lesson. > >If, as you say, potash is literally the potassium containing residue of >burned wood, are there such things as sulfate of potash and muriate of >potash? And if so, are they different in some way from potassium sulfate and >potassium chloride? I'm not asking you if the names exist - we already know >that these terms are common, at least in the older gardening literature. I'm >asking if there is such a thing as sulfate of potash which is distinct from >potassium sulfate and a muriate of potash which is distinct from potassium >chloride. >....... >Jim McKenney ************************************************* Jim Shields USDA Zone 5 Shields Gardens, Ltd. P.O. Box 92 WWW: http://www.shieldsgardens.com/ Westfield, Indiana 46074, USA Tel. ++1-317-867-3344 or toll-free 1-866-449-3344 in USA