Why is "prague powder" called "prague powder"?

"Prague Powder" is a product used to cure meat products such as hams and sausages. It is a mic od salt and sodium nitrite. It is marketed by several manufacturers, such as Morton (Tender quick, Instacure, ...). The original name for this curing mix is "Prague Powder". There are two kinds of "Prague powder". Prague powder #1 contains only Salt (Sodium Chloride) and Sodium Nitrite, Prague powder #2 contains Salt (Sodium Chloride), Sodium Nitrite and Sodium Nitrate. My question is: Why is it called "Prague powder"? I have looked in many books but haven't found the answer. I would like to know why it is called like that. I suspect it comes from the capital city of the Czech Republic, but I haven't be able to verify this fact. Why this name? Why Czech Republic? When did this product start to travel? I would like to know the answers=))