SUNDRY APPLICATIONS OF CASEIN. 143 



motion to facilitate the draining of the water ; after which it 

 is passed between rollers to squeeze out more of the water. 

 By means of an endless belt the pulp is next fed to a second 

 pair of rollers, after leaving which it still contains a consider- 

 able amount of water. It is cut up into squares, which are 

 placed between zinc plates ; and a number of these alter- 

 nating layers are put into a powerful hydraulic press, after 

 leaving which the pulp squares are hung up in a steam- 

 heated chamber, to get rid of the remaining moisture. 



Asbestos board can, of course, be made in varying thick- 

 nesses. The ordinary makes are composed of 6 to 12 and 

 even more layers, placed one above another and united by 

 passing them between rollers and in the hydraulic press. 

 The usual thicknesses are |, f, 1, 1-J-, 2, 2, 3, 4, 5 to 10 and 

 15 millimetres, and the sheets are generally 40 inches in 

 length and breadth. 



The chemical composition of the mass varies to an extra- 

 ordinary degree. Most kinds are greatty adulterated, con- 

 taining not more than 50 per cent, of asbestos, and that, too, 

 of inferior quality. It cannot be too strongly emphasised 

 that the valuable properties of the asbestos are the more 

 apparent in proportion as a better quality material is used, 

 and as trickery and adjuncts are shunned. 



PAPER FLASKS, ETC., FOR OILS AND FATS. 



Vessels of different shapes can be manufactured from 

 paper by reducing well-sized paper to pulp. A useful paper 

 for this purpose consists of about the following proportions : 



Rag 10 parts. 



Straw 40 



Brown cellulose 50 ,, 



The paper is impregnated with a solution of casein, in 

 order to render it impermeable and at the same time to 

 make the individual sheets of paper stick together. With 



