i | Lecithin. I 
nitrogen in their molecule, and from the standpoint of elementary 
analysis showed a marked disagreement with the theory. -This is 
well illustrated by the following table. 
Author. Source. C H N 1 Choline. 
per cent |per cent |per cent |per cent | per cent 
Thudichum....... Brain. 66.75| 18.67) 1.81 | 4.00 — 
Baskota see cee Liver. 64.64} 10.71] 1.95 | 4.00 — 
Hefiterte er. o — — a — 25 
Stern and Thier- 
felderiee av et Egg. 64.63) 10.96] 1.79 | 3.95 = 
MacLean®........ a ‘| 64.18} 10.60] 1-87 | 3.95 | 66 
Erlandsen‘®....... Heart. 66.29) 10.17] 1,87 |\*S205Nee 
MacLean’........ ie 66.27|-10:32| 1:85 °83 287s 
Bpplert a). 282 e 66.46] 10.69] 1.87 | 4.03 _ 
MacLean’........ ae — — | 1.89 | 4.04 | 68 
PONE Fite Not given. —.| — 11.85 :4:00Reeas 
Wa re NS From CdCl, salt. — | — | 1.87] 4.15 | 98.7 
The analytical data obtained by Ritter? on hydrolecithin 
showed better agreement with the theory, and one might be in- 
clined to regard the material of Ritter as such that it contained all 
the necessary proof in favor of the conventional theory. Unfortu- 
nately, Ritter did not determine the amino nitrogen content of 
the reduced lecithin, and hence failed to furnish definite proof of 
its purity. . 
‘Indeed, the present report contains data unmistakably prov- 
ing that hydrolecithin of an elementary composition fully har- 
monizing with the theory may be and generally is impure, con- 
taining between 10 and 20 per cent of its nitrogen in the form 
1 Thudichum, J. L. W., The Chemical Constitution of the Brain, Lon- 
don, 1884. 
2 Baskoff, A., Z. physiol. Chem., 1907, lvii, 395. 
3 Heffter, A., Arch. exp. Path. u. Pharm., 1891, xxviii, 100. 
4 Stern, M., and Thierfelder, H., Z. physiol. Chem., 1907, liii, 381. 
5 MacLean, H., Z. physiol. Chem., 1908, lv, 360; 1909, lix, 223; Biochem. 
J., 1909, iv, 38, 240. 
6 Erlandsen, A., Z. physiol. Chem., 1907, li, 71. 
7MacLean, Biochem. J., 1915, ix, 364. 
8 Eppler, J., Z. physiol. Chem., 1913, Ixxxvii, 241. 
* Ritter, F., Ber. chem. Ges., 1914, xlvii, 530. Cf. Reidel’s Ber., 1913, lvii, 
20; 1914, lviii, 15. 
