CASEIN ADHESIVES AND PUTTIES. 89 



boiling for some time, the mass being still kept stirred, and 

 finally cooled. If the glue is too thick, it may be thinned 

 down with a little ammonia. A good casein glue can also 

 be prepared from casein powder, magnesium chloride and 

 gelatinised starch. 



CASEIN SOLUTION. 



A solution, patented by the Casein Company of America, 

 is prepared by precipitating casein with hydrochloric acid, 

 and dissolving 1 part of the precipitate in 1 to 3 parts of 

 water with an addition of 0*1 to 0*12 part of trisodium 

 phosphate. 



A caseous mass, suitable for use as a bind or adhesive, 

 is obtained by mixing a solution of modified starch with 

 granular casein, the mixture being stirred rapidly until the 

 starch is absorbed by the particles of casein. The mass is 

 rendered alkaline during the process by adding a solution of 

 alkali. 



RENKEN'S METHOD OF USING GLUE. 



One side of the article to be glued is treated with for- 

 maldehyde, the other coated with casein putty, and the two 

 pressed together. Bottle lables and the like are moistened 

 with formaldehyde, dried and coated with casein glue. 



GLUE POWDER. 



To prepare glue powder, casein is mixed with powdered 

 slaked lime in suitable proportions, the mixture being stirred 

 up with water for use. A very good cement or bind is ob- 

 tained by mixing dry casein with levigated chalk, powdered 

 slaked lime and a solution of sodium silicate or borax. 



CASEIN GLUE. 



Bernstein prepares a substance with the properties of glue 

 by mixing casein with metallic silicates in the colloidal state. 

 With this object, the casein, either in skimmed milk or after 



