276 



FERTILIZERS. 



phosphoric acid with little or no nitrogen; 

 and bone, bat-guano, and Peruvian guano, 

 which contain considerable nitrogen with their 

 phosphoric acid. 



Potash. The chief supply of potash in fer- 

 tilizers is found in the German potash-salts, of 

 \v Inch there are several grades, the most import- 

 ant being the sulphates, muriates, and kainite. 



PRESENT SOURCES, CHARACTER, AND PROS- 

 PECTIVE SUPPLY OF COMMERCIAL FERTILIZERS. 

 A few facts concerning the mode of occur- 

 rence, character, and prospects of future sup- 

 ply of some of the more important commercial 

 fertilizers may not be out of place. For a num- 

 ber of statements here given we are indebt- 

 ed to an article on " Commercial Fertilizers : 

 Sources of Supply and History of the Trade," 

 by Dr. E. H. Jenkins, in the Report of the 

 Connecticut Board of Agriculture for 1881. 



Nitrogenous Fertilizers : Nitrate of Soda. 

 In Northern Chili, formerly Southern Peru, in 

 the province of Tarapac&, between the Andes 

 and the ocean, is a vast arid plain of table- 

 land, three thousand feet above sea-level, 

 stretching north and south for eighty miles. 

 The winds that blow steadily from the Andes 

 make an absolutely dry climate. The soil is 

 destitute of vegetation, and the territory is un- 

 inhabited. On this plain occur vast deposits 

 of nitrate of soda. It lies in strata five hun- 

 dred yards wide and seven or eight feet thick, 

 and in hollows looking like dried-up lakes, 

 whose sides are coated and bottoms covered 

 with the nitrate underlying common salt. The 

 origin of the deposits is undetermined. It is 

 conjectured that the nitrogen first came from 

 guano deposits on the shores of an inland salt 

 lake or sea, that through atmospheric agency 

 it was oxidized to nitric acid and then replaced 

 chlorine in the salt of the lake, and on evapo- 

 ration was left in its present shape. The crude 

 nitrate of soda is purified at the coast by solu- 

 tion, separation from sand, and recrystalliza- 

 tion, and shipped to Europe and the United 

 States. " In 1820 the first cargo was sent to 

 England, but was thrown overboard in harbor 

 because the duty was so high that it would not 

 pay to pass it through the custom-house. In 

 1830 a cargo came to the United States, but 

 found no sale. In that year 18,700 tons were 

 exported from Iquique; in 1840, 227,300 tons; 

 in 1850, 511,800 tons; in 1860, 1,370,200 

 tons; in 1870, 2,743,400 tons. In 1872 the 

 amount had risen to 4,000,000 tons, and in 

 the following year the Peruvian Government 

 took the matter into its own hands and decided 

 to export only 4,500,000 tons annually, so as to 

 keep the price constant. At present the re- 

 gion is in the hands of the Chilian Govern- 

 ment, and is likely to remain there. 



"Till now only one grade of nitrate of soda 

 has appeared in our market, and that has never 

 shown any fluctuation in composition, running 

 from 94 to 96 per cent of pure nitrate of soda, 

 with from 1 to \\ per cent of salt, 2 per cent 

 of water, and a very little insoluble matter." 



Sulphate of Ammonia. Another source of 

 nitrogen is found in ammonia salts, particu- 

 larly the sulphate of ammonia, which is now 

 chiefly obtained as a by-product in the gas- 

 manufacture. When of fair quality it should 

 contain from 16'5 to 20 per cent of nitrogen, 

 or from 77'7 to 94 per cent of the pure sal;. 

 Formerly our supply came mostly from Eng- 

 land, but of late it is being manufactured 

 largely in this country. It is stated that low- 

 grade sulphate of ammonia, with only 7 to S 

 per cent of nitrogen, is being imported hen-. 

 Such ammonia salts are apt to contain snlpho- 

 cyanide of ammonia, a substance rich in ni- 

 trogen but poisonous to plants. 



Animal Refuse : Dried Blood, Meat-Scrap, 

 etc. Another very important source of nitro- 

 gen for fertilizers is the offal of slaughter- 

 houses, which comes into the market under a 

 variety of forms and names : as, dried blood, 

 meat-scrap, azotin, ammonite, tankage, etc. In 

 the smaller slaughter-houses, the old way of 

 letting the offal run to waste still prevails, but 

 in the large establishments of both the East 

 and West, scarcely a pound of the solid matter 

 of the animals is left unutilized. 



The blood is drawn into tanks, the albumen 

 is coagulated and separated, the remaining solid 

 residue is dried by various methods, and sold as 

 dried blood, with from 9 to 12 per cent of nitro- 

 gen. It is a cheap, efficient, and valuable source 

 of this costly element. Tankage and meat-scrap 

 are names applied to the refuse flesh and viscera, 

 with often more or less bone, prepared by proc- 

 esses similar to those used for dried blood. They 

 are rich in nitrogen, and contain considerable 

 phosphoric acid also. Ammonite or azotin is 

 prepared from beef and pork " cracklings," the 

 refuse from tallow and lard melting, by extract- 

 ing them with benzine. 



Fish-Scrap Fish- Guano. One of the most 

 important sources of nitrogen for fertilizers in 

 this country is the refuse left after the extrac- 

 tion of oil from fish, especially the menhaden. 

 The early settlers of Massachusetts and Virginia 

 learned from the Indians to manure their corn 

 with fish, and it has long been the practice of 

 farmers on the Atlantic coast to spread men- 

 haden on their land for a fertilizer. Since the 

 menhaden began to be utilized for the extrac- 

 tion of oil, a cognate industry has been devel- 

 oped in the manufacture of a concentrated fer- 

 tilizer from the residual " pomace " or " scrap." 

 The first successful attempt to manufacture a 

 fertilizer from fish-scrap is credited to a Mr. 

 Lewis, of New Haven, Connecticut, in 1849. 

 The fish were steamed or boiled until disinte- 

 grated, pressed to remove the oil, and the press- 

 cake dried and ground. This is essentially the 

 process now employed, though more or less suc- 

 cessful modifications have been devised, espe- 

 cially to secure more complete extraction of 

 oil, which is a valuable commodity when sepa- 

 rated, but detrimental in the fertilizer. The 

 crude material is known as fish-scrap. When 

 dried and pulverized it is called fish-guano. 



