Read this recipe carefully and follow instructions. Soak one box Knox gelatine in one pint cold water, set on stove in double boiler to dissolve; when gelatine is cold and beginning to set, beat into it pineapple juice and pineapple, and place on ice to harden. Be sure you follow the above, for if you mix pineapple and its syrup with gelatine when you first make it, the acid in it will digest the gelatine so it will not harden.
Civic League Cook Book (1913).