224 CHEMICAL MAXUEES. 



factories he only works a few davs, and then rests under such condi- 

 tions ; the factories work very irregularly. The present prices are 

 about 10s. lOd. a cwfc. The rise in the price of nitrate which had 

 been discounted by the syndicate of manufacturers will always be 

 limited by competition with sulphate of ammonia. The latter, in 

 fact, after experiments made by Kraus at Weihenstephan, should 

 produce the same effect as nitrate, with this difference that it acts 

 more slowly. 



Ammoniacal Salts. — Ammonia is a compound of nitrogen and 

 hydrogen, according to the formula NH^, and forms a decomposition 

 product of nitrogenized organic matter. It is a gaseous body, giving 

 off a characteristic pungent odour. It is very soluble in water. 

 The solution is generally known as ammonia. It has an alkaline 

 reaction, and turns red litmus paper blue. Under the influence of 

 the oxygen of the air, ammonia is partially converted into nitric 

 acid. It forms salts with acids, by combining with these acids to 

 form a metalhc radical XH^ which is ammonium. Thus sulphate 

 of ammonia is formed according to the equation : — 



H,SO, + 2XH3 = (XHJ,SO, 



and ammonium chloride according to the equation : — 



HCl + XH. = XH.Cl. 



All ammoniacal salts give off ammonia when they are placed in 

 contact with alkalies or caustic lime. Ammoniacal compounds are 

 very widely distributed in nature, but always in small quantities. 

 Their presence has been determined in the air and in rain water, 

 also in the juice of almost all plants. Ammonium chloride is found 

 in salt springs, in volcanic emanations ; carbonate of ammonia in 

 large quantities in the guano deposits of Peru, Bolivia, and Chili, 

 and the western part of Patagonia. The principal sources of 

 ammonia for industry and for agriculture are certain substances of 

 animal origin (bone, meat, blood) or vegetable (coal, peat), which, 

 submitted to dry distillation, give off the greater part ot their nitrogen 

 as ammoniacal compounds. 



Ammonia is, likewise, obtained by the distillation of faecal 

 matters in presence of caustic lime and by the treatment of gas 

 (wash) liquor. Left to stand, urine putrefies ; the urea is trans- 

 formed into ammonia, which treated by caustic lime yields 

 ammonia and carbonate of lime. Ammonia is also found in the 

 smoke of factory chimneys and in coal soot ; the latter may even 

 sometimes be utilized as a manure, as the following analysis by 

 Hutton of Glasgow of coal soot shows : — 



Per cent. 



Potash 0-30 



Phosphate of lime ...... 3-20 



Ammonia ........ 2'80 



Equal to nitrogen 2-30 



