[Footnote: I allude to mineral salts as found in the vegetable kingdom, not to the manufactured salts, like the ordinary table salt, etc., which are simply poisons when taken as food.] fats and oils, carbo-hydrates (starch and sugar), and proteids (the flesh and muscle-forming elements).

He succeeded in isolating a substance corresponding in its chemical composition to grape sugar, and also a carbo-hydrate differing considerably from grape sugar, and turning the plane of polarization to the left.