62 CASEIN. 



40 per cent, formaldehyde (formalin) in 95 parts of water. 

 The degree of dilution depends on the amount of gloss 

 desired and on the absorbent character of the wall paper. 

 Generally speaking, equal parts of formolactin and the 

 said 2 per cent, solution of formaldehyde will be right for 

 good ordinary wall paper. If higher gloss is desired or the 

 paper is more absorbent, then 1 part of the 2 per cent, 

 solution can be taken to 2 parts of formolactin. For a 

 dull gloss and less absorbent paper the dilution may be 

 increased to 1 : 2. 



A wide, soft brush is used, and no more of the paint is 

 laid on than the paper will take up, otherwise it will trickle 

 down and a patchy appearance will be presented. 



The colour of most wall papers is made to look brighter 

 by a coating of this preparation, a fact which should be 

 borne in mind when the paper is being selected. 



After applying the coating it is left three to four hours 

 to dry, and the room is afterwards ventilated in order to get 

 rid of the smell of the formaldehyde. This may be accelerated 

 by sprinkling ammonia on strips of wadding and allowing it 

 to evaporate inside the room. The smell of formaldehyde, 

 however, is by no means injurious to health. 



If the first coating does not produce the desired lustre, or 

 fails to cover the paper properly, a second coating, properly 

 thinned, may be laid on without affecting the durability of 

 the covering. 



The best way to wash and clean wall papers coated with 

 this preparation is with lukewarm soap and water, to which 

 i to -^ per cent, of commercial formaldehyde has been added 

 as an antiseptic. 



WATERPROOF PAINT FOR PLAYING CARDS. 



Playing cards may be coated with a mixture of satin 

 white precipitated calcium sulphate and an alkaline solu- 



