120 CASEIN. 



slaked to powder. At the same time, 2 parts of neutral soap 

 are dissolved in 24 parts of water, and this solution is added 

 to the casein solution. The fabric is impregnated with this 

 preparation, and afterwards passed through a solution of 

 aluminium acetate, warmed to 120 to 140 F., whereby the 

 calcium caseate is rendered insoluble. After immersion for 

 an instant in nearly boiling water, the fabric is dried. 



ARGENTINE 



is the name given by Heim to a special powder, prepared 

 from zinc, which, when combined with casein, is or was 

 used for dressing yarn or fabrics in order to provide them 

 with a metallic finish. 



The method of preparation is based on the precipitation 

 of metallic tin in the form of powder, and on the use of 

 casein as a medium. The tin precipitate is obtained from 

 a solution of "tin salt" (stannous chloride) by the aid of 

 metallic zinc and the electric current ; and the powder, when 

 well dried, is bolted through fine gauze, the coarser particles 

 being redissolved for use over again. 



The casein is prepared by moistening 1 part of casein 

 powder with water for six to eight hours, after which it is 

 diluted with water containing \ part (referred to the casein) 

 of strong ammonia, so that the casein swells up and finally 

 becomes jelly. This is thinned with more water and stirred 

 up with the argentine, 1 part of which will stand the addition 

 of 1 to 1| parts of casein as a medium. Should the mass 

 thicken on standing, it is placed in a pan with warm water, 

 whereupon it is again ready for use. To make the printing 

 colour more workable it may also be mixed with some strong 

 gum, preferably light in colour and well strained. 



The casein solution may be also prepared in the following 

 manner, according as it is to be used as a dressing or for 

 printing: 2^ parts of casein are softened for ten to twelve 



