From 1922:
2oz. of gelatine, 1 ½ pints water, a good pinch of citric acid; 2lb. sugar, coloring and flavoring. For the white part, pineapple, lemon, or vanilla. Pink part: Color with cochineal. Flavor with raspberry, rose, or strawberry essence. Melt gelatine in the water, then add the sugar and dissolve it slowly; then let boil for 20 minutes, stirring all the time; add citric acid, and color and flavor to taste, pour into wet soup plates and leave for 24 hours; then cut up, and toss in icing sugar.