THE PREPARATION OF PLASTIC MASSES FROM CASEIN. 105 



camphor or the like material used in the manufacture of 

 celluloid. 



To obtain a homogeneous compound of nitrocellulose 

 and casein, Barnodai makes casein into a plastic mass with 

 an aqueous solution of borax or other casein solvent, removes 

 the excess of water, dips the mass in alcohol in order to 

 displace merely a portion of the water absorbed by the 

 casein, eliminates the excess of liquid, and then introduces 

 into the mass a quantity of elastic nitrocellulose, the whole 

 being kneaded until homogeneous. 



According to the Compagnie Frangaise a Celluloid, a 

 cheap substitute for celluloid is obtained by introducing casein 

 into the composition from which celluloid is prepared. One 

 hundred parts of casein are moistened with a solution of 5 

 parts of urea in 50 parts of denatured alcohol, and mixed, 

 after forty-eight hours, with nitrocellulose and camphor 

 moistened with alcohol. After another forty-eight hours the 

 mass is treated in the same way as celluloid paste, and it is 

 advisable to afterwards treat it with formaldehyde to render 

 the casein insoluble. 



CASEIN-CELLULOSE COMPOSITION. 



A composition suitable for many purposes and forming an 

 excellent electrical insulator and waterproof mass when sub- 

 jected to heavy pressure, can be prepared from cellulose and 

 an ammoniacal solution of casein. If necessary the mass 

 may be incorporated with repulped paper and some mineral 

 substance like magnesia, talc, kieselguhr and some body 

 colour. The casein may be replaced by pressed curd, and 

 the waste paper by alkali cellulose. In the latter event, the 

 alkali in the cellulose dissolves the casein, which thereupon 

 penetrates into the cellulose and furnishes a homogeneous 

 mass which can be incorporated with vegetable fibres or 

 powdered mineral substances and coloured with pigments. 



