114 



CASEIN. 



is advisable to free the casein from moisture, by evaporation 

 or pressure, before adding the formaldehyde. 



The product obtained in this way, and known as galalith 

 (from the Greek, gala = milk, and lithos^ stone) though it 

 cannot be regarded as petrified milk has been described by 

 Dr. K. Hassack as follows. The horny fundamental mass 

 can be converted into products of manifold colours and uses 

 by the incorporation of pigments, earths, cellulose, ground 

 cork, etc., with the casein previous to hardening it with 

 formaldehyde. Imitation jet or ebony, for instance, can be 

 prepared by adding 2 per cent, of lampblack and precipitating 

 with lead acetate, preferably in the warm to secure a curd 

 with less moisture. The precipitate is triturated with water, 

 and drained and carefully dried on a cloth strainer. Drying 

 must proceed very slowly to prevent cracking, and, therefore, 

 takes several months. The resulting dark grey cake is 

 thoroughly soaked with formaldehyde, and when dried and 

 polished is a glossy, deep black in colour. Other colours 

 may be obtained by varying the pigment. Thus, nickel 

 sulphate, used for throwing down the casein, gives a fine 

 green mass, whilst copper sulphate gives a peculiar bluish 

 green, and so on. Very good imitation marble is obtained 

 by stirring mineral pigments in with the freshly precipitated 

 casein, and particularly novel effects are furnished by mixing 

 bronze powders with the plain or coloured casein, before 

 hardening with formaldehyde. The Gummiwaaren Fabriken 

 (Rubber Works) of Harburg, Vienna, have produced at their 

 various works, by the aid of pressure, sheets of galalith from 

 ^ inch thick upward. By means of special tubular presses 

 they make galalith tubes and rods for turnery goods, knife 

 handles, penholders, umbrella and stick handles, chessmen, 

 cigar-holders and mouthpieces for same, small boxes, buttons, 

 dominoes, card counters, inlays for cups, coloured furniture 

 decorations to replace coloured glass. These and many other 



