even reaching to one-fourth of the total proteid matter;[178] but when so formed in the intestine it must entail a heavy loss of nutriment, for whenever the anti-group is split off after this fashion it becomes very resistant to the further action of the ferment. Separating in this manner from an artificial digestive mixture, it may be dissolved in dilute caustic alkali, reprecipitated by neutralization, and then once again brought into solution with dilute sodium carbonate. In this form, it will yield some antipeptone by the further action of trypsin, although even then a large amount of the antialbumid is prone to separate out as a gelatinous coagulum, more or less resistant to the further action of the ferment. [177] Chittenden and Goodwin: Journal of Physiol., vol. xii., p. 36. [178] Kühne und Chittenden: Ueber die nächsten Spaltungsproducte der Eiweisskörper. Zeitschr. f. Biol., Band 19, p. 196. The peculiar action of trypsin, however, as a proteolytic enzyme is shown in the production of a row of crystalline nitrogenous bodies of simple constitution whenever the ferment is allowed to continue its action for any length of time, either on native proteids or on proteolytic products containing the hemi-group. This, to be sure, is a fact long known, but it gains added significance as year by year new bodies are discovered as products of trypsin-proteolysis with various forms of proteid matter. The very character of the bodies originating in this manner gives evidence of the far-reaching decompositions involved; decompositions which are perhaps attributable as much to the innate tendencies of the proteid material as to the specific action of the ferment. As representatives of this peculiar line of cleavage, we have first the well-known bodies, leucin and tyrosin; leucin, a body belonging to the fatty acid series, long known as amido-caproic acid, but now generally considered as amido-isobutylacetic acid, (CH_{3})_{2} CHCH_{2} CH(NH_{2}) COOH; and tyrosin, a body belonging to the aromatic group, having the formula OH ╱ C_{6}H_{4}⧼ ╲ CH_{2} CH(NH_{2}) COOH, and known as oxyphenyl-amido-propionic acid.