"Nitrogenous extractives" of flesh, _i.e._, of meats and fish.
These include kreatin and allied compounds, and are the
chief ingredients of beef tea and most meat extracts.
Amids: this term is frequently applied to the nitrogenous
non-albuminoid compounds of vegetable foods and feeding
stuffs, among which are amido acids, such as aspartic acid
and asparagin. Some of them are more or less allied in
chemical constitution to the nitrogenous extractives of
flesh.

_Fats._

Fat of meat: fat of milk; oil of corn, wheat, etc. The
ingredients of the "ether extract" of animal and vegetable
foods and feeding stuffs, which it is customary to group
together roughly as fats, include, with the true fats,
various other substances, as lecithians, and chlorophylls.

_Carbohydrates_, sugars, starches, celluloses, gums, woody fibre, etc.

_Mineral matter._

Potassium, sodium, calcium and magnesium chlorids, sulphates
and phosphates. (Atwater).

The terms (_a_) "nitrogenous" and (_b_) "carbonaceous" are frequently
used to designate the two distinct classes of food, viz.: (_a_) the
tissue builders and flesh formers; (_b_) fuel and force producers.