NATURE AND PROPERTIES OF THE SOIL. 3i 



whether our limestone contains any portion of magnesia. It ie 

 only pernicious when applied in an excessive dose; and Uns 

 holds equally true with respect to ime, for these two eaithe 

 should, in all cases, be used sparingly by the skdful cultivator. 

 Loam is by no means a distinct body, possessing m itselt ap- 

 propriate and marked characters, as many of our farmers sup- 

 pose : but is a combination of clay, sand, or calcareous matter. 

 The diversity which exists among what are accounted loams, is 

 a decisive proof of this; some of them we denominate clayey, 

 from the excess of argillaceous matter ; others open and light, 

 from the preponderance of sand. Mould, as it is sometimes 

 called, contains the putrid relics of organized substances t^i at 

 have grown auil decayed upon it, or have been conveyed tluther 

 in the prooress of cultivation. The resident earth remaining 

 after the process of dissolution, is extremely lio'ht m weight, 

 and always of a blackish color. It is owing to this, that a gar- 

 den which has been under long continued culture, approaches 

 to a black tinge, progressively deepening, according to the a- 

 bundance of this matter. Soils lying in the territory of an old 

 countrv, are found to contain various chemical compounds, min- 

 eral salts, and metallic oxids; some of which are beneficial, 

 others harmless, and a few injurious to vegetation ; and which 

 either pre-existed in the strata from which the surface has 

 been formed, or have been carried to it by subterraneous 

 sprino-s, or by foreign causes, operating in the course ot past 

 ao-es^The most frequent are epsom and common salts combin- 

 ations of potash, lime and magnesia, with the acid and oxid ot 

 iron, which is just the rust produced by exposing this metal to 

 the action of the air. It is this oxid which gives the 

 brown and redish color, as well as the intermediate shades, to 



sand and clay. , u j • 4 



It seems plain that considerable advantages may be derived 

 to the practical farmer, from analyzing the different kinds of 

 soils, from comparing the proportion ot the earths in the pro- 

 ductive, with those found in the barren, from studymg the 

 separate effects of these ingredients, and from ail these re- 

 sults, deducing the most skilful plan of procedure m effec- 

 tuating permanent improvements. But the usual process 

 which the learned chemist would adopt, m analyzmg soils, 19 

 too laborious and intricate for practical use to farmers in gen- 

 eral. The following simple process is within their reach, and 

 may lead them to adopt for themselves more accurate and per- 

 fectmethods. In the field to be examined, take earth, a little be- 

 low the surface, from four separate places, about 1-4 if', avoir- 

 dupois, from each. Expose it to the sun, or before the fire, tiii 



