Sentence:  The sturgeon yielded a non-food product that was important for domestic and commercial use. This was <WSD>isinglass</WSD>, a gelatinous substance that was derived from the inner membrane of the air bladder (also called the swimbladder, or sound). <WSD>Isinglass</WSD> had a variety of uses. The Ojibway valued it as an effective binding agent in the manufacture of paint. <WSD>Isinglass</WSD> was also a product much in demand in Europe during the fur trade period. It was noted as producing a high quality glue and as a fining agent for beers and wines. 
Meaning of the word marked with <WSD> tags:  A form of gelatine obtained from the air bladder of the sturgeon and certain other fish, used as an adhesive and as a clarifying agent for wine and beer.