Book II. ANALYSIS OF SOILS. 221 



Sect. III. Of discovering the Qualities of Soils. 



1035. The value of soils to the cultivator t is discoverable botanically, chemically, and 

 mechanically ; that is, by the plants that grow on them naturally ; by chemical analysis ; 

 and by exterior and interior inspection or handling. 



Subsect. 1. Of discovering tlie Qualities of Soils by means of the Plants which groiu 



on them. 



1036. Plants are the most certain indicators of the nature of a soil ; for while no prac- 

 tical cultivator would engage with land of which he knew only the results of a chemical 

 analysis, or examined by the sight and touch a few bushels which were brought to him, 

 yet every gardener or farmer, who knew the sort of plants it produced, would be at 

 once able to decide as to its value for cultivation. 



1037. The leading soils for the cultivator are the clayey, calcareous, sandy, ferrugineous, 

 peaty, saline, moist or aquatic, and dry. The following are the plants by which such 

 soils are distinguished in most parts of Europe : — 



Argillaceous. Tussilago farfara, Potentilla anserina, argentea, and reptans. Tha- 

 lictrum flavum, Carex, many species. Juncus, various species. Orobus tuberosus, 

 Lotus major, and corniculatus. Saponaria officinalis. But the Tussilago farfara is 

 a certain and universal sign of an argillaceous soil, and is the chief plant found on the 

 alum grounds of Britain, France, and Italy. 



Calcareous. Veronica spicata, Gallium pusillum, Lithospermum officinale, and pur- 

 puro-caeruleum. Campanula glomerata, and hybrida. Phyteuma orbicularis, Verbas- 

 cum lychnitis, Viburnum lantana, Berberis vulgaris, Cistus helianthemum, Anemone 

 Pulsatilla, Clematis vita alba, Hedysarum onobrychis. 



Siliceous. Veronica triphyllus, and verna. Echium italicum, Hernaria glabra, and 

 hirsuta. Silene anglica and other species. Arenaria rubra, &c. Spergula arvensis, 

 Papaver hybridum, Argemone, &c. 



Ferrugineous. Rumex acetosa, and acetosella. 



Peaty. Vaccinium myrtillus, uliginosum, and oxycoccus. Erica 4 sp. Spergula 

 subulata. Tormentilla officinalis. 



Saline. Salicornea 4 species. Zostera marina, Ruppia maritima, Pulmonaria mari- 

 tima, Convolvulus soldanella, Illecebrum verticillatum, Chenopodium maritimum, 

 Salsola kali, and fruticosa. Sium verticillatum. Arenaria maritima, &c. Atriplex 

 laciniata. 



Aquatic. Caltha palustris, Hippuris vulgaris. Pinguicula vulgaris, Lycopus euro- 

 peus, Valeriana dioica, Viola palustris, Samolus valerandi, Silenum ^alustre, Epilobium 

 tetragonum, Lythrum salicaria, Ranunculus lingula, and flamula. 



Very dry. Arenaria rubra, Rumex acetosella, Thymus Serpyllum, Acinos vulgaris, 

 Trifolium arvense. 



1038. These plants are not absolutely to be depended on, however, even in Britain ; 

 and in other countries they are sometimes found in soils directly opposite. Still, 

 the saintfoin is almost always an indication of a calcareous soil; the common 

 coltsfoot (Tussilago farfara), of blue clay; the arenaria rubra, of poor sand; the 

 small wood-sorrel of the presence of iron. The aquatic, peaty, and saline soils are 

 almost every where indicated by their appropriate plants ; a proof, as we have 

 before stated, that the climate and natural irrigation of plants have much more influence 

 on their habits than mere soil. (See the Stationes Plantarum of Lin. and the Flora 

 Franqaise of De Candolle ; Galjnne's Compendium Fl. Brit. ; Smith's Flora Brit. ; 

 Kent's Hints; and Farmers' Mag. Feb. 1819.) 



Subsect. 2. Of discovering the Qualities of Soils by chemical Analysis. 



1039. Chemical analysis is much too nice an operation for general purposes. It is not 

 likely that many practical cultivators will ever be able to conduct the analytic 

 process with sufficient accuracy, to enable them to depend on the result. But still such 

 a knowledge of chemistry as shall enable the cultivator to understand the nature of the 

 process and its results, when made and presented to him by others, is calculated 

 to be highly useful, and ought to be acquired by every man whose object is to join theo- 

 retical to practical knowledge. If it so happens that he can perform the operations 

 of analysis himself, so much the better, as far as that point is concerned ; but 

 on the whole, such knowledge and adroitness is not to be expected from men who have 

 so many other points demanding their attention, and who will, therefore, effect their pur- 

 pose much better by collecting proper specimens of the soils to be studied, and sending 

 them for analysis' to a respectable operative chemist. 



1040. In selecting specimens, where the general nature of the soil of a field is to be 



