NITROGENOUS MANURES. 243 



In the boiler G the water which only contains a portion of the 

 ammonia liberated by the lime comes in intimate contact with 

 the steam, which is injected through the perforated coil d. The 

 steam forced by the concentric sides of I to rise along the gradations 

 of the column becomes charged with the ammonia it meets, and 

 passes by the pipe m into the pipe n, which forces it to traverse 

 the liquid of the milk of lime chamber. The ammoniacal vapours 

 afterwards rise into the rectifier, and finally when they are entirely 

 deprived of water they pass through the pipe j) into the saturation 

 vessel D. The bad-smelling non-condensable gases are collected 

 in the bell q, whence they return through r and s into the reheater ; 

 finally they are burnt in a special furnace. The milk of lime is 

 injected by the pump C into the still through the pipe c. Stills of 

 this type have been installed capable of treating 5500 to 7920 

 gallons of ammoniacal liquor in twenty-four hours. They work 

 •economically and require little superintendence. 



Bemarks. — Continuous stills should be entirely of cast-iron. 

 Copper and bronze should not be used, for they are rapidly corroded 

 hj the ammoniacal vapours. The presence of ammonium sulphide 

 in the ammoniacal liquor is very annoying in work. This body 

 gradually corrodes even cast-iron vessels. Therefore, iron reservoirs 

 are sometimes replaced by cement ones. According to Kunheim, 

 gas liquor may be freed from sulphur by a strong current of air, 

 the effect of which is to decompose the ammonium sulphide into 

 H2S and NH3.1 



Manufacture of Suljjhate of Ammonia from Urine. — Amongst 

 organic matters putrid urine is one of the most important sources 

 of ammonia. The putrefaction of urine gives rise to the formation 

 of carbonate of ammonia, seeing that urea C0N.2H^ contains two 

 molecules of water. An adult produces on an average 30 grm. of 

 urea, which corresponds to an annual production of 24-2 kg. or 

 ■53'2 lb., nearly ^ cwt., of sulphate of ammonia.^ 



As the carbonate of ammonia is very easily decomposed into 

 CO2 and NH3, it has been thought advisable to utilize it in the 

 manufacture of sulphate of ammonia. Figuera used the following 

 apparatus for the purpose. In the furnace V is the boiler W, which 

 propels steam into the wrought-iron cylinders C C containing about 

 100 hectolitres (2200 gallons) by the pipes T and T'. The two 

 cylinders are charged with putrid urine. The ammonium carbonate 

 vaporized passes by T" into the lead coil e in vat A ; it condenses 

 with the water and passes in the state of solution into the vessel S 

 filled with sulphuric acid, where it is converted into sulphate of 



iBut ammonia distillers are prohibited in Great Britain from letting 

 HgS escape. — Tr. 



2 Say, for the whole 5,000,000 odd population of London, 2,500,000 cwt. of 

 sulphate of ammonia, worth say £1,250,000, run into the Thames and carried 

 out to sea armually. — Te. 



