Even greater differences in inner chemical structure are found among native proteids. By way of illustration, we may take egg-albumin, the casein of cow’s milk, gliadin of wheat, and the edestin of hemp seed. These are all typical proteids; they are all useful as food, but they are radically different in their inner chemical structure, as is clearly indicated by the following data,[21] which show the percentage yield of the different amino-acids and ammonia: [21] These data were furnished the writer by Dr. Thomas B. Osborne, and represent in large measure the results of his own chemical work. +--------+-------+--------+----------+--------+------+---------+--------+ | | | |Glutaminic| | | | | | |Leucin.|Tyrosin.| Acid. |Arginin.|Lysin.|Histidin.|Ammonia.| +--------+-------+--------+----------+--------+------+---------+--------+ |Egg- | | | | | | | | | albumin| 6.1 | 1.1 | 9.0 | ... | ... | ... | 1.6 | |Casein | 10.5 | 4.5 | 10.7 | 4.8 | 5.8 | 2.6 | 1.9 | |Gliadin | 5.7 | 1.2 | 37.3 | 3.2 | 0 | 0.6 | 5.1 | |Edestin | 19.9 | 2.7 | 14.0 | 14.2 | 1.6 | 2.2 | 2.3 | +--------+-------+--------+----------+--------+------+---------+--------+ These are not mere technical differences, but they represent divergences of structure which cannot help counting as material factors in nutritional processes. Especially noticeable is the large yield of glutaminic acid from wheat proteid, as contrasted with the proteid (casein) of animal origin. As a rule, glutaminic acid forms a larger proportion of the decomposition products of vegetable than of animal proteids. Similarly, arginin is present in much larger proportion in most vegetable proteids than in most animal proteids. While many other data more or less trustworthy might be added, these figures will suffice to emphasize the main point under discussion, viz., that individual proteids show marked variation in the amount of the several amino-acids which serve as corner-stones or nuclei in the building up of the molecule, and consequently they must yield correspondingly different katabolic products when serving the body as food.