134 BOTANICAL MICROTECHNIQUE. 



nuclein preparations of various authors as compounds of 

 nucleic acids with various amounts of albumen. 



[Malfatti (II) has prepared an artificial nuclein from syn- 

 tonin and metaphosphoric acid, which yields nucleic acids 

 when treated by Altmann's method.] 



236. Zacharias has recently (I and 1 1) attempted to recog- 

 nize microchemically the general distribution of nucleins, 

 especially in cell-nuclei. He gives as a characteristic reac- 

 tion for them, their insolubility in pepsin and hydrochloric 

 acid (cf. 233), in which, as well as in .2-.$$ hydrochloric 

 acid, they take a sharply defined and peculiarly glistening 

 appearance. But the nucleins are, according to Zacharias, 

 soluble in a 10$ solution of common salt, in a concentrated 

 solution of sodium carbonate, in dilute caustic potasJi solution, 

 in concentrated hydrochloric acid, and in a mixture of four 

 parts concentrated hydrochloric acid with three parts water. 

 Further investigations must show how far the macrochemi- 

 cally prepared nucleins and those recognized by the above 

 reactions correspond with each other. 



[According to Malfatti (I) and Zacharias (V), the nucleins 

 seem to constitute the so-called chromatin-bodies of the 

 nucleus (cf. 239).] 



c. Plastin 



237. Reinke (I) prepared a nitrogenous compound from 

 the plasmodia of ALthalium septicum, which he calls plas- 

 tin. According to Zacharias (I and II), this compound rep- 

 resents the fundamental substance of the cytoplasm and 

 agrees in its microchemical behavior with nuclein, in not 

 being attacked by pepsin with hydrochloric acid and in being 

 soluble in concentrated hydrochloric acid. But plastin differs 

 from nuclein in not swelling in a 10$ solution of salt after 

 treatment with pepsin, and in being less readily soluble in 

 alkalies and insoluble in a mixture of four parts of pure con- 

 centrated hydrochloric acid and three parts water. 



It remains to be learned whether plastin is really a single 

 compound or includes a group of related compounds. Ac- 



