You can look it up on the 'net if you really need the info. And, interestingly enough, there are many other sources of potassium (the primary nutrient in potash) that you can use which are pretty inexpensive. Here's a link I checked out (just because I was interested in finding out about it).
Fertilizer potassium is sometimes called potash. Potassium is removed from the soil in harvested crops and must be replaced to support future crop growth.
www.cropnutrition.com
Matter of fact, that is one of the things I find this board useful for, finding out stuff, because some posts make me wonder about the stuff they are saying, and because I've got an internet connection (which means access to the world's largest library), I can easily check out whatever strikes my interest.
Not doing anything other than saying your post made me curious, and here's some info I found that you might find useful.