THE PREPAKATION OF PLASTIC MASSES FKOM CASEIN. Ill 



is effected into a perfectly clear solution, containing the 

 casein, whilst the opaque particles are deposited as sediment. 



Further experiments have shown that warmth, concen- 

 trating the solution, and prolonged standing, all favour the 

 separation, which, moreover, can be effected very quickly by 

 a single addition of alkali. Casein solutions prepared with- 

 out alkali, and even milk itself, can be converted in this 

 manner into a clear solution and a precipitate. The result- 

 ing clear liquid is colourless, greenish-yellow, brownish or 

 red, according to the degree of contamination and to the 

 temperature employed. 



Since the various technical varieties of casein exhibit 

 different conditions of solution, in consequence of the 



