48 AMERICAN AGRICULTURE. 



mixed with the muck heap. Its great affinity for water, has 

 the effect, like that of gypsum, of attracting dews arid at- 

 mospheric vapor to the growing vegetation, but in a still 

 greater degree. By this means, a copious supply of moisture 

 is secured to those plants which have been thus manured, 

 and far beyond what is experienced in adjoining fields. Salt 

 is also useful in destroying slugs, worms, and larvse, which 

 frequently do much injury to the crops. 



SULPHATE OF SODA, (G-lauber Salts,) SULPHATE OF MAGNESIA, 

 (Epsom Salts,)AND SULPHATE OF POTASH. 



These are all useful manures, and they act on vegetation 

 in a manner similar to gypsum. This was to have been ex- 

 pected, so far as the sulphuric acid is concerned, which is 

 common to each ; but their action is modified to a certain 

 degree, by the influence which the bases or alkaline ingredi- 

 ents of these several salts exert upon the plants. The gene- 

 rally-increased price which they bear over gypsum, will pre- 

 vent their use, when remote from those localities where they 

 exist in a state of nature ; or where they may be procured 

 at low rates, near the laboratories in which they are rnanu 

 factured. 



NITRATE OF POTASH, (Saltpetre,) AND NITRATE OF SODA. 



These are both extensively found in a crude state in na- 

 tive beds, or as an efflorescence ; and in this condition, they 

 can frequently be bought at a price that will justify their 

 use. The first contains potash,46.5, and nitric acid,53.5 ; the 

 second, in its dry state, soda, 36. 5, and nitric acid, 63. 5, in 

 every 100 parts. Numerous experiments have been tried 

 with them on various crops; but they have not thus far, af- 

 forded very accurate or satisfactory results. In general, they 

 give a darker color and more rapid growth, and they in- 

 crease the weight of clover, the grasses and the straw of 

 grain ; and the forage is also more relished by cattle. But 

 in the average effects upon grain and roots, the statements 

 are too much at variance to deduce any well-settled princi- 

 ples, which we might safely assume as a reliable guide to the 

 practical agriculturist. From the decidedly beneficial ef- 

 fects produced hi numerous instances, may we not reasona- 

 bly infer, that they have generally been successful where 

 there has been a deficiency of them in the soil ? 



As a soak or steep for seeds, and especially when dis- 

 solved and added to the bed where they are planted, there 

 is no doubt of their possessing some value, in giving an early 



