314 REPORT ON NITRIFICATION. 



or at least as requiring less recondite investigations to bring them 

 into practical operation. We know of various plans hy which the 

 conversion of ammonia into nitrates has been effected, and can devise 

 many more by which, in all probability, it would be effected. The 

 first point to be considered, in connexion with this, is the means of 

 supplying ammonia. 



Ammonia is largely produced in the manufacture of coal gas, from 

 which, after leaving the retorts, it is removed ; partly by condensa- 

 tion as ammoniacal liquor; partly by a sort of mechanical entangle- 

 ment in the lime purifier; and sometimes by the agency of water, with 

 Avhich the whole body of gas is washed; and sometimes, also, a special 

 purifier is used for the ammonia, whose presence in the gas is injuri- 

 ous. The ammoniacal liquor is sometimes used for the manufacture 

 of compounds of ammonia, sometimes as a manure, but frequently is 

 allowed to run to waste. From the amount experimentally obtained 

 from coal, it has been estimated that the ammonia producible from 

 one ton would form about seven pounds of sulphate of ammonia.* 

 If the ammonia in this were nitrified it would produce 10.71 pounds 

 of saltpetre . This amount of ammonia is probably not all produced 

 from coal by the ordinary distillation for gas, and what is evolved is 

 in large part not collected. 



The cheapest of the salts of ammonia in use is the sulphate, Avhich 

 costs eighty or ninety dollars a ton ; a large part of Avhich cost is 

 that of the sulphuric acid used in its manufacture. A ton of this, if 

 used for the production of saltpetre, would produce about 3,300 

 pounds of the latter. A rectified ammoniacal liquor, at one time 

 sold in England, afforded ammonia at one-third of the expense in- 

 curred by buying" it in the form of the sulphate. It was obtained by 

 distilling the liquor of the gas-works, but never came into general 

 use. 



The sulphate of ammonia is used largely as a nitrogenous manure, 

 and for this purpose the ammoniacal liquor itself is not very available 

 since most of it is produced during the winter, when it cannot be 

 applied to land, and the ammonia being volatile cannot easily be kept, 

 unless it is converted into a non-volatile compound. 



For the purpose of generating nitre the ammoniacal liquor could 

 be used as fast as produced, either being condensed into a portable 

 bulk for transportation or used on the spot. That part of the am- 

 monia which escapes condensation in the gas liquor may be removed 

 from the gas by various methods, one of which now in use is that of 



* Analysis by J. C. Wrightson. Estimates of the ammonia obtainable from coal are, 

 many of them, considerably greater than this; but some assertions that have been made 

 with regard to the large amounts of this and of other products got from coal by certain 

 methods of distillation are to be received with suspicion. The assumption that all the 

 nitrogen contained in coal is given oif as ammonia during distillation must be altogether 

 erroneous, and only deserves mention because it has recently been advanced, apparently 

 without suspicion of its fallacj'. Thus we find upon sucli grounds the extravagant estimate 

 made that one ton of coal will produce a hundred weight of sulphate of ammonia. — 

 (Chemist, 1855, p. 339.) Taking the estimate which I have given iu the text, the gas- 

 works of the city of London produce enough ammonia for the formation of about 2,000 

 tons of saltpetre annually. 



