240 



CHEMICAL MANUEES. 



Steam Stills. — The intermittent, naked fire stills have been 

 replaced by continuous stills fitted with a rectification column 

 similar to those used in alcohol distilleries. Such a column, the 

 working of which is uniform and continuous, renders it possible 

 to work much more economically. *• Amoncrst the best known stills 



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Fig. 45. — De Lair's Still. 



A. Distilling column composed of circular segments of cast-iron. B. Milk of 

 lime mixer. C. Milk of lime pump. D.D. Exchange heaters. Entrance 

 of milk of lime into column. E, Gas escapement. 



of this nature, those of De Lair, Feldmann, and Gruneberg may be 

 quoted. 



Feldmann s Still. — The ammoniacal liquor contained in a 

 reservoir a flows into a measurer h, passes through the pipe c 

 fitted with a valve r into a tubular reheater j, rises through d 

 into the rectifier A, and meets the vapours which deprive it of all 



