238 - • CHEMICAL MANUEES. 



said, the ammoniacal vapours formed in the pans A and B pass into 

 C and D, then into the condenser. The milk of hme is prepared 

 in the reserv-oir E, whence it passes into the still B by the pipe 

 M. The still A is emptied from time to time, say every three days ; 

 the discharged liquid is then replaced by an equal quantity of 

 ammoniacal liquor coming from the stills B, C, and D. The con- 

 densed water in the vessel Y may be emptied into the vessel D 

 throuo-h the pipe 0. For that purpose the three-way tap Z, which 

 brint^s two of the pipes entering D into communication, is fixed in 

 the rit^ht place for the ammoniacal vapours not to pass into the 

 refrigerator F, but into the reservoir Y. 



The absorption vessel is lead lined and filled with the sulphuric 

 acid intended to make sulphate of ammonia. The latter is put to 

 drain in E, the mother liquor flows into X, and thence into the 



absorption vessel. 



The air refrigerator T is only used when it is desired to make 

 liquor ammonia. In the manufacture of sulphate of ammonia it 

 is replaced by a cylinder 10 ft. high and 20 in. in diameter, into- 

 which the pipe bringing the ammoniacal vapours dips, until just 

 above the bottom. By fitting the cylinder with an overflow pipe, 

 matters are so arranged that it is always one-third full. The water 

 from the overflow pipe flows into the collecting vessel Y. The 

 furnace is shown in Q. The combustion gases first impinge on 

 the still A, and then pass under the still B. The Mallet stills at 

 work at the Yillette Gas Works produce 10 tons of sulphate of 



ammonia dailv. 



Lunges Still. — This still is based on the same principle as the 

 preceding, but it is much more simple ; a is the still, b is the pipe 

 leading the vapours to the condenser c. The refrigerator d is fed 

 by ammoniacal liquor ; it communicates with the still by the pipe 

 e. The contents of the still may be run out by the pipe /, which 

 is closed when the still is at work by a valve g. The lime which 

 is deposited at the bottom of the boiler is again brought inta 

 suspension by the agitator //. The tap on the pipe i is opened 

 when the liquid from the refrigerator d is heated to the point of 

 giving off ammoniacal vapours ; the latter pass through i into the 

 pipe "^h, and afterwards into the coil c, mixing with the vapours 

 coming from the still a. When the vapours have traversed the 

 washer h thev pass by the pipe m fitted with a safety arrangement 

 into the lead-lined wood absorption vessel /, containing sulphuric 

 acid to absorb the ammonia. The acid flows from the reservoir o 

 throucrh the syphon }) into the absorption vessel I. Its arrival 

 is regulated so "^that the liquid in the absorption vessel is always 

 acidf The vapours given off collect under the hood r, whence they 

 are forced into the chimney or burned in the furnace. The sul- 

 phate of ammonia deposited at the bottom of the vessel / is emptied 

 bv a bucket hung to a chain and counterpoise t. 



