This all makes sense, Jim. A century ago, and longer, the existing manufacturing processes did not produce the high purity we can attain today in chemical compounds. Potassium and sodium are both present in all living things (and in their ash residues). Sodium is also present in most natural deposits of potassium. Sodium and potassium are hard but not impossible to separate by crystallization. The sodium salt (chloride, sulfate, whatever) crystallizes out first and the potassium remains in the mother liquors (that really is a technical term) along with some left-over sodium. Concentrate the liquids and repeat the process. Eventually the potassium starts to crystallize out too. You and I, like most other living things, need sodium as well as potassium. I still would not want to buy fertilizers that I knew contained sodium and chloride. Jim Shields At 11:16 AM 3/30/2013 -0700, Jim McK. wrote: >The discussion we had earlier this week about the identity of muriate of >potash seemed to provide a simple solution: that muriate of potash was the >same thing as potassium chloride. > >Now I've read something which makes me wonder. One source (the T H Everett >Encyclopedia of Gardening from the 1960s) makes the claim that muriate of >potash is 85% potassium chloride and 15% sodium chloride. > >That was written a half century ago. Can any of our chemists comment on >whether that might have been true back then but is/is not true now? > >It seems to me that if muriate of potash contains 15% sodium chloride, >then it's not the same thing as potassium chloride - certainly not the >same thing as Jim Shields' $100/oz potassium chloride. > >Table salt might be good for some plants (I've read that it's good for >asparagus), but many plants are sensitive to it - and who wants to pay >muriate of potash prices for table salt? > >Jim McKenney ************************************************* Jim Shields USDA Zone 5 P.O. Box 92 WWW: http://www.shieldsgardens.com/ Westfield, Indiana 46074, USA Lat. 40° 02.8' N, Long. 086° 06.6' W