186 PEACH LEAF CURL*. ITS NATURE AKD TREATMENT. 



added percentage of water. It is always desirable to specify the 

 strength of the ammonia solution when obtaining quotations. 



Plants and animals furnish the main sources of commercial ammonia. 

 In each case the ammonia is obtained through the decomposition or 

 destructive distillation of the organic matter. Mr. Mallinckrodt, of 

 the Mallinckrodt Chemical Works, of St. Louis, and president of the 

 Pacific Ammonia and Chemical Company, states that there are, as 

 already indicated, but two prime sources from which aqua ammonia is 

 obtained, viz, "bone liquor," obtained as a by-product in the manu- 

 facture of bone coal, and "gas liquor," obtained from the scrubbing 

 of gas in works for the manufacture of coal gas. A similar source is 

 also found in the making of coke. It is further stated that ammonia 

 is obtained from bone liquor almost exclusively in the form of sulphate 

 of ammonia, often of crude quality, which is used in the manufacture 

 of fertilizers. Gas liquor is partly worked, into a sulphate of superior 

 quality, but mostly into aqua ammonia, by what is called the direct 

 process. It is redistilled and aqua ammonia made therefrom. Aqua 

 ammonia obtained from this source is largely used in the manufacture 

 of ice and for other technical purposes. Obtained in this way, it is 

 said to be the cheapest article of good quality that can be supplied. 



A crude concentrated ammoniacal liquor is also largely made by 

 concentrating gas liquor without puritication. This concentration is 

 carried on mainly at smaller works for the purpose of transporting the 

 liquors in a more concentrated form, to save the expense of freight, to 

 works where crude liquor is redistilled and manufactured into pure 

 aqua ammonia. The concentrated liquor is, however, also largely used 

 in the preparation of nitrate of ammonia, which is used in the manu- 

 facture of powder, but most largely in the manufacture of soda ash. 

 This crude liquor contains, besides a small amount of free anmionia 

 (NHg), a considerable amount of carbonate, sulphide, cyanides, and 

 other ammonia salts, together with tarry and empyreumatic matter 

 resulting from the destructive distillation of coal. The strength of 

 this liquor can not be made greater than 15 to 20 per cent, and it is 

 doubtful if it could be advantageously used as a substitute for aqua 

 ammonia in the preparation of sprays. The ammoniacal liquors obtained 

 in the manufacture of coal gas are entirely a by-product. 



As the gas works of the United States have been largely supplanting 

 coal gas with water gas, in the manufacture of which ammonia is not 

 obtained, the quantity of ammonia produced in the country has been 

 steadily decreasing, and the demand is being supplied principally from 

 England. Both aqua ammonia and anhydrous ammonia are made 

 largely from imported sulphate of ammonia, and very large quantities 

 of the imported article are also consumed in the manufacture of 

 fertilizers.^ 



^San Francisco's quotation on ammonia water of 26° hydrometer test, in drmns of 

 about 750 pounds, f. o. b., is 7 J cents per pound. 



