... or less, of "insoluble fatty acids,'' while margarine contains about 95.5%; 5 grammes of butter-fat when chemically decomposed yield an amount of volatile fatty acids which requires about 26 cubic centimetres (more or less) of deci-normal alkali solution for neutralization, while margarine requires mostly less than 1 cubic centimetre (Wollny or Reichert-Meissl method). There are other differences between the two kinds of fat: the specific gravity of butter-fat is higher than that of most other fats; its power of refracting a ray of light is less; the ... — Project Gutenberg Encyclopedia
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