HIGTI GRADE NITROGENOUS FERTILIZER MATERIALS 57 



cause of poor transportation facilities. There are also deposits 

 of bat guano in Texas. The bat guanos are not as a rule as 

 valuable as the high grade nitrogenous Peruvian guanos.* 



Ammonium sulphate is unlike the organic compounds as it is 

 not a natural product but a manufacturing by-product. When 

 pure it is a white crystalline salt but sometimes foreign substances 

 become mixed with it, in the course of manufacture, which causes 

 it to be grey, yellow, or blue. It is soluble in water and vola- 

 tile, that is, it will pass off as gas when strongly heated over a 

 flame. It is derived from the distillation of coal in the manu- 

 facture of gas ; from the distillation of bones in the manufacture 

 of bone-black; and from the manufacture of coke from coal. 

 Coal was formed from vegetable matter and most coals average 

 about 1.8 per cent, nitrogen. When coal is heated, as in the 

 manufacture of gas or coke, about ji of the nitrogen as am- 

 monia is driven off and this ammonia may be saved by washing 

 it in water in special apparatus. The solution thus formed is 

 then distilled into sulphuric acid, concentrated and the crystals of 

 sulphate of ammonia separate out on standing. Bones contain 

 about 3 to 4.5 per cent, nitrogen and the nitrogen as ammonia 

 is recovered in a similar way as in distilling coal or coke, when 

 they are subjected to dry distillation by heat, as may be practiced 

 in the manufacture of bone-black.* 



Composition and Availability. — Sulphate of ammonia when pure 

 contains 21.2 per cent, nitrogen but the commercial article usually 

 runs about 20 per cent. It is in a form very suitable for distri- 

 bution in the soil and is readily converted into available plant 

 food. It is more available than the organic forms. It is a quick 

 acting fertilizer and suitable therefore for quick returns in crop 

 production, an especial advantage for truckers and market gard- 

 eners. It is sometimes substituted for nitrate of soda. 



As it is readily soluble in water it should be used sparingly, and 

 frequent small applications are more effective than large amounts 

 applied at long intervals. A continued use of it may cause the 

 soil to become acid because of the sulphates left in the soil after 

 the nitrogen is given up.* 



