PLASTER OF PARIS 59 



being already somewhat soaked will not show the 

 same thirst when the time comes for using it. All 

 damp and, still more, all wet plaster is of no further 

 use. 



"Statues, busts, medallions, and various other 

 ornamental objects are made by casting with fine 

 plaster of Paris. This is prepared from the purest 

 gypsum, those beautiful transparent scales I told 

 you about a little while ago. It is heated in ovens 

 similar to those used by bakers, and cut off from 

 contact with the burning fuel, so as to preserve its 

 whiteness. The powder, which looks like fine flour, 

 is mixed with water and reduced to a smooth paste, 

 which is then poured into molds. When the plaster 

 has set, the mold, which is in several pieces, all 

 joined together, is taken apart and the finished cast 

 withdrawn." 



