104 CASEIN. 



is pressed, and dried at 140 F. The mass is powdered, and 

 70 parts of it are mixed with 28 of bone meal, gypsum, 

 kaolin, or graphite, together with 2 parts of stearin, paraffin, 

 wax, etc., and colouring matter if necessary. The whole is 

 made into a pulp and warmed at 190 F., moulded and 

 pressed, the finished product being dusted over with calcined 

 magnesia, immersed in water for two days, and finally dried 

 at 68 F. 



PRODUCTION OF PLASTIC MASSES FROM CASEIN. 



To obviate the necessity for employing acids in the pre- 

 paration of plastic masses from casein, Kathe merely heats the 

 casein with water to a high temperature, at which the former 

 undergoes a change of character. The amount of water the 

 casein will absorb varies slightly according to the degree of 

 purity of the material itself, but is independent of the quantity 

 of water employed for heating. Thus, if one part of casein be 

 heated with ten parts of water, the resulting plastic mass is 

 the same as if the proportions were only two to one. The 

 granular casein changes into a coagulated, coherent mass, 

 similar to caoutchouc, and from which all the water that is not 

 chemically combined can be removed, leaving a soft, uniform 

 substance, which, on compression and cooling, furnishes articles 

 of considerable hardness, and only needing a few days' drying. 

 The casein may also be heated in moulds, with the necessary 

 amount of water, superheated by steam. 



PLASTIC MASS FROM CELLULOID. 



The inflammability of celluloid can be diminished by the 

 addition of incombustible substances, of which casein is one ; 

 and this application of casein has already been repeatedly 

 advocated and employed 



According to Dunham, a product resembling celluloid 

 can be obtained by mixing solutions of casein and nitrocel- 

 lulose in glacial acetic acid or other known solvents, with 



