88 CHITIN. NUCLEIN. 



is the characteristic product. l A similar decomposition is observed 

 when sulphuric acid p is employed. 



Glycosamin (C 6 H 13 N0 6 ). Crystallises from alcohol in fine needles, 

 is dextrorotatory, and reduces Fehling's fluid to the same extent as does 

 dextrose, but is not fermentable. By treatment with nitrous acid a 

 carbohydrate (C 6 H 12 O 6 ) (?) is obtained which also reduces cupric 

 oxide, but is similarly unfermentable. This is doubtless the sub- 

 stance 'which led to certain erroneous statements as to the production 

 of a true dextrose from chitiu. 2 



Nuclein. C 29 H 49 N 9 P 3 22 (?). 



The nuclei of cells, both animal and vegetable, differ distinctly 

 in chemical composition from the remaining substance of the cells. 

 As a result of this difference it is possible to separate the nuclei 

 approximately by various means from the adjacent cell-substance. 

 The name nuclein is given to the material of which the nuclei or 

 parts of nuclei thus isolated chiefly consist. When, however, the 

 statements of the various authors who have dealt with nuclein 

 are compared with regard to the reactions, decompositions, and 

 more especially the percentage composition of their preparations, 

 it appears probable that 110 definite substance exists to which the 

 one name nuclein may be fitly applied. It may be that_the dis- 

 crepancies are due to the existence of several kinds_QJLjmclein ; 3 

 but this, is_as yet scarcely proved^and it is on the whole" more 

 probable that the different results of the various Authors must be 

 attributed to the impurity of the substance on which~they^op- 

 erated. 4 In accordance with this viewTt is to be observed that 

 the percentage of phosphorus obtained in even the most reliable 

 analyses is stated to vary from 2'3 to 9'6 p.c. 



After the above precautionary remarks we may now give an 

 account of the preparation and properties of the so-called nuclein. 

 When a mass of cells such as pus, 5 yeast, 6 nucleated red blood- 

 corpuscles, 7 salmon-milt, 8 or egg-yolk 9 is extracted with water and 

 dilute (-5 p.c.) hydrochloric acid, the cells are largely broken up 



1 Ledderhose, loc. cit. and Ibid. Bd. iv. (1880), S. 139. 



2 Berthelot, Compt. Rend. T. XLVII. (1858), p. 227. Journ. de la Phi/siol. T. n. 

 p. 577. 



3 Hoppe-Seyler, Hdbch. d. physiol.-path. chem. Anal. (5 Auf.), 1883, S. 303. 

 Phi/siol. Chem. S. 85. 



* Worm-Miiller, Pfluger's Arch. Bd. vm. (1874), S. 190. Bunge, Physiol.-pathol. 

 Chem. (Transl. by Wooldridge, 1890), p. 89 



5 Miescher, Hoppe-Seyler s Med.-cliem. Untersuch. Hft. iv. (1871), S. 452. Hoppe- 

 Seyler, Ibid. S. 486. 



" 6 Hoppe-Seyler, Ibid. S. 500. Kossel, Zt. phi/siol. Chem. Bd. in. (1879), S. 284 ; 

 iv. (1880), S. 290; vn. (1883), S. 7. Unters. ub. d. Nudeme u. ihre Spaitunc/sprod . 

 Strassb. 1881. Loew, Pfluger's Arch. Bd. xxn. (1880), S. 62. 



7 Bruntou, Jl. Anat. and Phi/stol. 2 Ser. Vol. in. 1869, p. 91. Pldsz, Hoppe- 

 Seyler's Med.-chem. Unters. Hft. iv. (1871), S 461. 



" 8 Miescher, Verhand. d. Natforsch. Geseil. Basel, Bd. vi. (1874), S. 138. 



9 Miescher, Hoppe-Seyler's Med.-chem. Unters. Hft. iv. (1871), S. 502. Worm- 

 Miiller, loc. cit. 



