606 BRAIN AND NERVES. 



The extractive bodies seem to be almost the same as in the muscles. 

 One finds creatine, which may, however, be absent (BAUMSTARK), purine 

 bases, inosite, choline, paralactic acid (MORIYA), phosphocarnic acid, uric 

 acid, and the diamine neuridine, C5Hi4N2, discovered by BRIEGER l 

 and which is most interesting because of its appearance in the putrefac- 

 tion of animal tissues or in cultures of the typhoid bacillus. Among 

 the enzymes we must mention catalases, peroxidases, Upases and amylases 

 ( WR6BLEWSKi) . According to the autolytic experiments of SIMON 2 

 a proteolytic enzyme, and an enzyme acting upon the organic phos- 

 phorized substance with the splitting off of phosphoric acid also occur. 

 Under pathological conditions leucine and urea have been found in the 

 brain. Urea is also a physiological constituent of the brain of cartilagi- 

 nous fishes. 



Several of the lipoids occurring in the brain have been discussed in 

 previous chapters, and we will here only speak of the protagon and the 

 cerebrosides. 



Protagon. Under this name LIEBREICH described a crystalline, 

 nitrogenous and phosphorized substance, which has been found in the 

 brain of man, mammalia and also birds (ARGIRIS) but not in the brain 

 of fishes (ARGIRIS). Its elementary composition, according to GAMGEE 

 and BLANKENKORN, is C 66.39, H 10.69, N 2.39 and P 1.07 per cent. 

 The results obtained by CRAMER correspond well with these figures and 

 he found that protagon also contained sulphur which had previously been 

 found by RUPPEL and by KOSSEL. Recently WILSON and CRAMER 3 have 

 reported more recent analyses and they find for protagon, recrystallized 

 4-5 times, almost the same figures as GAMGEE and BLANKENHORN, namely, 

 C 66.53, H 10.97, N 2.37, P 0.95 and S 0.73 per cent. They consider 

 protagon as a unit substance. 



GIES, POSNER and ROSENHEIM and TEBB 4 dispute the unit nature 

 of protagon. They have found, on fractional precipitation or on recrys- 

 tallization, that protagons can be obtained from the various solvents, 

 having variable composition, especially different P and N contents. They 



1 Brieger, Ueber Ptomaine, Berlin, 1885 and 1886. 



2 Wr6blewski, Compt. Rend., 152; Fr. Simon, Zeitschr. f. physiol. Chem., 72. 



3 Liebreich, Annal. d. Chem. u. Pharm., 134; Argiris, Zeitschr. f. physiol. Chem., 

 57; Gamgee and Blankenhorn, ibid., 3; Kossel and Freytag, ibid., 17; Ruppel, 

 Zeitschr. f. BioL, 31; Cramer, Journ. of Physiol., 31, with R. A. Wilson, Journ. of 

 exp. Physiol., 1, with Lockhead, Bioch. Journ., 2; also Cramer, Quarterly Journ. of 

 exp. Physiol. 3, and Bioch. Handlexikon (Abderhalden) Bd. 3, which contains the 

 literature. 



4 Gies and Lesem, Amer. Journ. of Physiol., 8; Posner and Gies, Journ. of biol. 

 Chem., 1; Gies, ibid., 3; Rosenheim and Tebb, Journ. of Physiol., 36 and 37, Quarterly 

 Journ. of exp. Physiol., 2, and Bioch, Zeitschr., 25. 



