68 SCIENCE PROGRESS. 



(i.) Ammonia. 



(ii.) An amido-acid of the acetic series, viz., leucine, 

 (iii.) Two amido-acids of the acrylic series, viz., as- 

 paraginic acid C 4 H 7 NO, (amido-succinic acid), 

 and glutaminic acid C 5 H 9 NO + (am ido-pyro tar- 

 taric acid), both of which were found in con- 

 siderable quantities. On one occasion the glut- 

 aminic acid amounted to as much as 29 per 

 cent, of the weight of dry casein used, 

 (iv.) Tyrosine or oxyphenyl-alanine. 

 It is thus seen that, as with the action of barium 

 hydrate, the result of this decomposition is to lead mainly to 

 the formation of amido-acids. 



Ritthausen 1 was the first to separate glutaminic and as- 

 paraginic acids from proteids. He obtained glutaminic acid 

 from legumin and conglutin, and Kreusler examined 

 animal proteids treated in a similar manner, but failed 

 to isolate it. He consequently suggested the view that 

 it was a typical product of the decomposition of vegetable-, 

 but absent from animal-proteids. Hlasiwetz and Haber- 

 mann, 2 however, obtained it in considerable quantities 

 from casein, albumin, and several other proteids. It is 

 interesting to note that the glutaminic acid here isolated 

 is laevorotatory, whilst that obtained by Schiitzenberger 

 was only found in small quantities and inactive. By 

 boiling the active form with barium hydrate, however, 

 it becomes converted into the inactive form, and further, 

 this inactive form, or that obtained by Schiitzenberger's 

 process, if allowed to ferment under the action of Peni- 

 cillium glaucu?n, becomes transformed into the optically 

 active modification. 3 



Employing the same method, Horbaczewski 4 obtained 

 from gelatin, leucine, glutaminic acid and glycocine, but 



^Jonrn.f. praktische Chemie, 107, p. 218, and 99, p. 454. 



2 Anz. der K. Akademic zu Wien, ix., p. 114, 1872. 



3 Berichte der deutschen Chemischen Gesellschaft, 17, 388. Changes in 

 the optical varieties of leucine have been produced by exactly similar 

 methods. 



4 Sitz. der K. Akad. zu Wien, bd. 80, Abthlg. 2, s. 101, 1880. 



