82 THE CHEMICAL CONSTITUENTS OF THE NUCLEI. [BOOK I. 



disappears. Occasionally this appearance and disappearance may be 

 observed to occur many times in succession. It is pretty obvious that 

 this phenomenon is due to the coagulation by the C0 2 of a proteid 

 existing around the nucleus, and which is probably identical with 

 paraglobulin, the re-solution under the influence of oxygen agreeing 

 with the known characters of that body. 



The Nuclei of the Red Corpuscles. 



If we except the blood of adult mammals that of all other vertebrates 

 contains red corpuscles possessed of a nucleus. This may, whilst 

 the corpuscle is living and unaltered, be scarcely if at all perceptible, 

 but readily comes into view when weak acids or carbon dioxide exert 

 their action. 



Composed I D Order to investigate the chemical composition 



according to of the nuclei of coloured blood corpuscles, the blood of 

 Brunton of a birds (and also of snakes) has been employed. In 

 mucin-iike j^g researches, carried on under the direction of Kuhne, 

 Dr Lauder Brunton 1 followed the following process. 

 Defibrinated blood from the bird was treated with ten or twelve 

 times its volume of 3 per cent. NaCl solution, and the corpuscles 

 separated by nitration and decantation. On shaking the residual 

 mass of corpuscles with water and ether, the nuclei of the corpuscles 

 are set free from the stroma, and float at the junction between 

 the water and ether. 



In order further to separate the nuclei from adhering stroma 

 and colouring matter, the agitation with ether and water may 

 be repeated several times and the residual matter washed with 

 dilute hydrochloric acid, hot alcohol and ether 2 . From his obser- 

 vations Brunton came to the conclusion which Kiihne had previously 

 arrived at, viz. that the nuclei of the blood corpuscles are composed 

 of a substance closely resembling, if not actually identical with 

 mucin. He found that they were insoluble in HC1 of 01 to 1 

 per cent., but soluble in solutions of the alkalies, the solutions 

 thus obtained being precipitated by the addition of mineral acids, 

 the precipitate being redissolved by an excess of acid. The solutions 

 were precipitated by acetic acid, the precipitate not being soluble in 

 excess, but were not precipitated by solution of mercuric chloride. 



Nuclei of Plosz, repeating these experiments of Brunton, con- 



blood cor- firms the statement that the body composing the nuclei 



puscies said resembles mucin in its properties ; on subjecting it to 

 analysis, however, he found that it contained phos- 

 phorus, and he therefore considers it to be identical 



1 Brunton, "On the chemical composition of the nuclei of Blood-corpuscles." 

 Journal of Anatomy and Physiology. Second series. Vol. in., p. 91. 



* Plosz, "Ueber das chemische Verhalten der Kerne der Vogel- und Schlangen- 

 blutkorperchen," Hoppe-Seyler, Med. Chem. Untersuchungen, Heft iv. (1871) p. 460. 



