CHAP. II.] THE BLOOD. 83 



with the body separated by Miescher 1 from the nuclei of pus-corpuscles 

 and by him termed NUCLEIN. This body, which will be treated of 

 fully under ' pus,' is unacted upon by gastric juice, so that bodies 

 composed of it (e.g. the nuclei of the red blood corpuscles) may be 

 purified by subjecting them to artificial digestion. 



The Nuclein of Miescher contains 9 '59 p. c. of P, and to it the 

 formula C^H 49 N 9 P 3 O 22 has been ascribed. This formula must be 

 received with great caution. 



Fatty matters containing Phosphorus (Lecithin, Protagon?). 



Berzelius and Lehmann were aware that the corpuscles contained 

 a fatty body or bodies containing phosphorus, and the second of 

 these observers determined that the ash of the blood corpuscles 

 contains phosphoric acid and has an acid reaction. A closer study 

 of the phosphorized proximate principle of the coloured corpuscles 

 was, however, made by Gobley 2 , and afterwards by Hermann 3 and 

 Hoppe-Seyler 4 . 



Having dissolved the blood corpuscles in water, Hermann agitated 

 the solution repeatedly with ether. The ethereal solution was decanted 

 and evaporated, when it was found to leave a crystalline deposit 

 consisting of cholesterin and tufts of a body which Hermann considered 

 identical with the substance shortly before separated by Liebreich 

 from the brain and called by him PKOTAGON. 



In order to purify this substance Hermann added water to the 

 mixed crystalline deposit left by the ether ; the effect of the water is 

 to cause the protagon to swell and to become less soluble in ether ; 

 by the latter reagent the substances soluble in ether are then 

 separated. The residue is dissolved in alcohol heated to 50; and 

 from the alcoholic solution protagon is obtained in a crystalline form. 



Of late years Hoppe-Seyler and, after him, nearly all physiological 

 chemists have come to consider protagon as not being a definite 

 proximate principle but as a mixture of a phosphorized body called 

 lecithin C^H^NPO^ with a body termed cerebrin C 31 H 33 NO 3 , and 

 it is the former substance which, according to Hoppe-Seyler, is con- 

 tained in the red blood corpuscles. These surmises in reference to the 

 non-existence of protagon have however been disproved by the author, 

 who has shewn that protagon is a perfectly definite proximate 

 principle. The observations of Hoppe-Seyler and Jiidell, however, 

 would appear to be irreconcilable with the view that the coloured 

 corpuscles contain protagon 5 . 



1 Miescher, "Ueber die chemische Zusammensetzung der Eiterzellen." Hoppe- 

 Seyler, Med. Chem. Untersuchungen, Heft iv. (1871) p. 441. 



2 Gobley, Journ. de Pharm. et de Chemie, Ser. in., T. xxi., p. 250. 



3 Hermann, Archiv f. Anat. u. PhysioL, 1866, p. 33. 



4 Hoppe-Seyler, " Ueber das Vorkommen von Cholesterin und Protagon und ihre 

 Betheiligung bei der Bildung des Stroma der rothen Blutkorperchen." Med. Chem. 

 Untersuchungen, Heft i. (1866) p. 140. Also Gustav Jttdell : "Zur Blutanalyse," 

 Hoppe-Seyler's Med. Chem. Untersuchungen, Heft in. (1868) p. 386. 



5 Gamgee and Blankenhorn, "On Protagon." Journal of Physiology, 1879. 



62 



