What is bulldog soda fertilizer?

Bulldog is/was a brand name for sodium nitrate fertilizer which was "mined" in Chile. I'm not sure if it is still available. It was a white granular mineral fertilizer, high in nitrogen, with no other plant nutrients. It was applied like any other dry fertilizer, and like most of them it would harden into clumps if exposed too long to high humidity. Bulldog is/was a brand name for sodium nitrate fertilizer which was "mined" in Chile. I'm not sure if it is still available. It was a white granular mineral fertilizer, high in nitrogen, with no other plant nutrients. It was applied like any other dry fertilizer, and like most of them it would harden into clumps if exposed too long to high humidity. The company that distributed this brand was Champion. There is/was a picture of a bulldog on the multi-layer paper bags in which it was sold.