n 



The process going in inside is watched through a 

 hole in the door of the kiln, and when it is observed 

 that the gas has ceased escaping from the pots, the 

 operation is finished. With a properly managed 

 lire, it should take from to ^ hours to complete the 

 calcination. 



For the charcoal to be good, it must be properly 

 bin-lit] nnbnrnt bones are easily noticed on account 

 of their weight, which is greater and their density. 

 The insufficiently burnt bun s must be picked out 

 and burnt over. 



When an expert views new animal charcoal and 

 has to test it at sight, he takes in to account its 

 weight, its color, which should be a fine dull black 

 and at the same he should put a pier-,' in his mouth. 

 If the charcoal adheres strongly to his tongue and 

 bi,i.c.s it, and if the color is good, he .says thai the 

 charcoal is good. 



Hones give about 60 p,.T con! of llioir weigh! iu 

 animal charcoal. 



When the bones have been calcined, the charcoal' 

 is not yet ready for use : it should be broken into 

 pieces of about 3 or 4 eighths of an inch in diameter 7 

 this is done in a pounding mill. We then have what 

 is called noir en yrains (seed charcoal), and it is in 

 this form that it is used to filter juice and syrups 



Charcoal that has been used for filtering, should 

 before being again used, be cleaned and revivified. 



In fact it has absorbed from the juice and syrup 

 certain azote substances, coloring matter, lime, salts 

 of potash and soda, which 'must be taken out. 



