1 66 LESSONS IN CHEMISTRY. 



which it completely destroys, as an application to grass-land. 

 It is usually applied at the rate of 6 tons to the acre, and is 

 sold in Belfast at Is. 8d. per ton. At present, this substance, 

 which might be usefully employed were its proper treatment 

 generally known, is, I am informed, thrown away at several 

 gas establishments. 



261. Ammoniacal liquor of the gas-worhs. — The prepara- 

 tion of coal-gas exhibits several beautiful applications of 

 chemical knowledge; thus, the manufacturer finds in lime a 

 cheap and effectual means of purifying the gas from carbonic 

 acid and sulphuretted hydrogen, the presence of which would 

 materially affect the brilliancy of its flame ; and is also ena- 

 bled, by a peculiar arrangement of his apparatus, to separate 

 from it certain liquid products which possess considerable 

 commercial value. One of these is the watery fluid known 

 as gas, or ammoniacal liquor. This liquor is found to hold in 

 solution variable quantities of the carbonate and other salts of 

 ammonia. It is at present, in many places, used for the pre- 

 paration of a salt called sulphate of ammonia, which is formed 

 by adding sulphuric acid to it, and evaporating to dry- 

 ness. You may recollect that it is this compound which is 

 produced, when sulphuric acid or gypsum is mixed with fer- 

 menting urine. Sulphate of ammonia has been used, with 

 good effects, as an application to both wheat and potatoes;* 

 1 00 lbs. of it usually contain 35 lbs. of ammonia, but it is 

 occasionally adulterated with sulphate of soda (52) and 

 other cheap salts.f Its present wholesale price in London is 

 165. per cwt. The gas liquor can be obtained at a very 

 low price, and has been found a useful manure for grass and 

 clover. It should be diluted, before its application, with 3 

 or 4 times its bulk of water, and its effect will be rendered 

 more peimanent by neutralizing it (13) with some sulphuric 

 acid, or by mixing some gypsum with it to fix the ammonia. 

 It is appHed at the rate of 100 gallons per acre. 



262. Lime, salt, and peat-mould. — A compost formed of 



* The application of a mixture of sulphate of ammonia and vitriolized 

 bones, has been found exceedingly useful in improving the verdure and 

 destroying the moss which springs up in old worn-out lawns. 1 ^ cwt. 

 of the sulphate of ammonia, and 5 bushels of bones, will be sufficient for 

 an acre. 



f The teacher may readily test the pm-ity of a sample of sulphate of 

 ammonia, by heating a little of it, on the pomt of a knife, over the spirit- 

 lamp, when, if pure, it will all be converted into vapour. 



