I know Jim McK. likes language and its history. Muriate of potash and sulphate of potash are historical or alchemical terms. The modern scientific names for these compounds are potassium chloride for "muriate of potash," and potassium sulfate for "sulphate of potash." The correct names for chemical compounds are defined by the International Union for Pure and Applied Chemistry. Just as plant names and animal names are regulated by international scientific organizations in those fields, so are chemical names. If there is a difference between "sulphate of potash" and potassium sulfate, I suppose it might be in purity and degree of characterization, but there is probably no way of knowing. Chloride is toxic to plants at higher levels, so it's never a good idea to use chloride salts in fertilizers. It therefore helps to know if there is chloride in your fertilizer, which isn't obvious if we talk about "muriates." Hearing "muriate of potash" and "sulphate of potash" strikes my ears the same way hearing "ain't" and "hain't" does now, too. They are all soooooo 19th century. Which is alright if you'd rather be living in the 19th century, I guess. I'm just a chemist of the 20th and 21st centuries. If you're having a scientific discussion, there is no question which terminology is correct. If you're having a literary discussion, that's a different matter. Regards, Jim Shields At 11:46 AM 3/29/2013 -0700, you wrote: >Jim Shields wrote: " I find it interesting that gardeners and even >educated horticulturalists still use names like "muriate of potassium" or >"sulfate of potash" which >went out of use in chemistry in the late 19th century. Quaint." > >Jim, can you expand on this please? > >Let's take the term muriate of potash for starters, since that's what I >used my post. Is muriate of potash the same as muriate of potassium? If >both of these terms are outdated, what do you suggest as alternatives? > >With regard to muriate of potash, that term is widespread in the >horticultural literature (maybe what you would call the outdated >horticultural literature?). Older books warn against using muriate of >potash with potatoes or roses. I've noticed that some commercial >formulations intended for use with roses do not use muriate of potash and >instead use another potassium source, even when formulations from the same >manufacturer use muriate of potash in other of their products. . If >muriate of potash is an outdated term, what term should we be using? > >Is your objection to the term sulfate of potash the form of the term? In >other words, do you prefer potassium sulfate (and does it mean the same >thing?). > > >Jim McKenney >_______________________________________________ >pbs mailing list >pbs@lists.ibiblio.org >http://pacificbulbsociety.org/list.php >http://pacificbulbsociety.org/pbswiki/ ************************************************* 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