106 OF FERTILIZERS. 



they must have the same effects as ashes, only in a more 

 decided manner. 



35-1. The salts of ammonia, especially the nitrate, are 

 very valuable as manures, and are particularly applicable 

 to soils already rich in phosphates, or which contain vege 

 table acids. Sulphate of Ammonia, which may be obtained 

 at a moderate price at the manufactories of gas, is excel 

 lent, when applied in small quantities, to fields of meadow 

 hay or of wheat. 



355. Nitrate of Potash, East India saltpetre, is nitric 

 acid and potash united. As might be expected, botli 

 nitrate of potash and Nitrate of Soda, South American 

 saltpetre, yielding not only nitrogen but potash and soda 

 to plants, are particularly beneficial to wheat and to 

 barley. 



356. And, as the plants grown in the fields must supply 

 the phosphate of lime which is essential to the growth of 

 the bones of all animals, and this ingredient in soil is 

 likely to be exhausted, Phosphate and Super-phosphate of Lime 

 are of the very greatest value as manures. Phosphate of 

 lime is usually applied in the shape of ground bones, and 

 super-phosphate, as bones dissolved by sulphuric acid and 

 diluted with water, applied either in a liquid state, or 

 reduced to powder .by drying. 



357. All the elements in the salts of ammonia, of potash 

 and of lime,- here spoken of, are either taken up by plants, 

 or exert a most important influence upon the humus in 

 the soil, hastening the process of decay, and converting 

 insoluble into soluble salts. 



358. Common salt is also sometimes of great value as 

 ;L i ertili/er. For some plants, asparagus, for example, it 

 is of indisputable importance, and may be employed in 

 very large quantities. It not only enriches the soil for 



