189 



sel above the sulphur apparatus, and is allowed to enter the 

 box through the pipe shown at the top of the diagram. 



As soon as the stream of liquid encounters the first shelf 

 it spreads out over the whole of the surface exposed to it, 

 and flows in a thin layer down shelf after shelf until it 

 reaches the exit tube at the bottom of the apparatus. 



The sulphur furnace can be constructed of a few bricks 

 laid either in moist clay or mortar, while the pipe connect- 

 ing the furnace with the box can be constructed of sheet 

 iron, or else a piece of 1| or 2 inch gas pipe can be em- 

 ployed. 



An opening is left in one side of the furnace to assist the 

 draught, while the sulphur is burned in a small iron pot or 

 pan, ordinary roll sulphur or brimstone being the form best 

 adapted to this purpose. 



The fumes enter the apparatus near the bottom as shown 

 in the cut and, in passing through the box, follow the course 

 indicated by the arrows and dotted lines, the juice as it flows 

 downward being continually met by a stream of sulphur 

 fumes passing upward. 



The employment of this form of apparatus insures the 

 ready absorption of the sulphurous acid gas by the juice, 

 and a very marked change is observed in the character and 

 color of the juice as it flows from the box, as compared with 

 the juice fresh from the mill. 



The juice, after sulphuring, is allowed to flow into the 

 first compartment, of the evaporator, and when it has almost 

 reached the boiling point, a small amount of a thin milk of 

 lime is added, the juice, however, being left distinctly acid 

 as indicated by litmus test paper. 



As soon as boiling commences, and frequently before the 

 boiling point is reached, it will be observed that large 

 quantities of froth and scum have accumulated on the sur- 

 face, and can be removed in the usual manner as fast as 

 they are formed, a very clear bright juice being obtained 

 in a very short time. 



The evaporation is now conducted, in the usual manner, 



