274 



FARxMERS' REGISTER 



[No. 5 



therefore, the latter miji^ht be viewed as affording 

 a pretty correct index to tiie composition of tlie 

 former. Nothing, however, as will iaimeditUely 

 be seen, can be more fallacious, f;s a test of the 

 nature and qualities of a soil, than the herbage it 

 gives rise to. Many plants certainly have each a 

 particular soil, in which alone they apj;ear fitted 

 by structure and habit to attain perlectiun, and ihey 

 either thrive or languish, according to the whole- 

 some or hurtful nature of the iiigredients which 

 supply their wants; but there are several material 

 circumstances to be taken into consideration, be- 

 sides the chemical and mechanical constitution of 

 the earths to which they adhere, belbrc we can 

 arrive at anything like conclusions as to the regu- 

 larity with which particular compositions become 

 the abode of certain species. "The number of 

 plants," says I\!r. A. Gorrie, "which may serve 

 as a test for pointing out the peculiarities of soil, 

 is comparatively small; many are found to prosper 

 equally on ditferent soils, and the means wliich 

 nature employs to cover the surlace of our globe 

 with verdure, are so well adapted for accom[)lish- 

 ing that purpose, that it affords matter of aston- 

 ishment to find, in the vegetable creation, an ap- 

 proximation to locality in certain plants, which 

 may enable us to assign to each, its favorite nidus 

 in cultivation, or to distinguish that nidus by their 

 spontaneous growth." It is, therefore, not to be 

 wondered that difficulties of no ordinary kind 

 should be experienced in attempting to fix with 

 certainty the circumstances under which a given 

 plant may be expected to shovv itself on a particu- 

 lar soil, or that an almost insurmountable barrier 

 should be presented to our progress in endeavor- 

 ing to discover even a lew plants, that will only 

 grow upon one variety of ground. In the vege- 

 table kingdom, we have evidence to prove that 

 certain effects can only, in some instances, owe 

 their occurrence to one, or, at most, two proxi- 

 mate causes — as, for example, where heath inva- 

 riably indicates the existence of a peat, and where 

 the common whin as regularly points either to a 

 bed of clay, or to one of loam, on a gravelly sub- 

 soil; but instances of the kind are rare, compared 

 with the frequency with which plants in general 

 appear to be the result, mdiscriminately, of many 

 causes, and to be assigned to no particular soil. 

 Thus, alders and willows seem indifferent as to 

 what may be the mixture in which they fix their 

 roots, provided that a copious supply of water be 

 constantly afi'orded them, and hence they are (bund 

 to denote rather the proximity of a lake or stream, 

 than the presence of any one in particular of the 

 usual constituents of a soil. 



The limits of vegetables are never so abruptly 

 defined, as to admit of their being spoken of with 

 certainty. Nature does not distribute her produc- 

 tions with undeviating regularit)', or with the rigid 

 adherence to boundaries of a practised gardeiier. 

 We never see one order of plants ranked side by 

 side, over an extensive surface, with another of 

 dissimilar character, yet kept entirely apart from 

 the ground appropriated to its fellow. If soils pos- 

 sessed of peculiar inirredients afforded a hospita- 

 ble bed for certain plants, but formed, at the same 

 time, an unapproachable barrier to others, we 

 might certainly expect to see their limits at least 

 as well defined as those of the rocks of v\rhich these 

 soils are formed; but as plants do not bear unex- 

 ceptionable relations to particular soils, and flour- 



ish, in many cases, on any of a vast variety of mix- 

 tures, without apparently evincing a preference, so 

 it is impossible to tie them to a locality, or to assign 

 a distinct limit, beyond which they will not prosper, 

 "From what we know," says Mr. Macgillivray, 

 at the commencement of his Inferences, "of the 

 constitution of the world in general, and lioni what 

 we have observed of Scotland in particular, we are 

 led to infer, in the first place, that soil has little in- 

 ffuence upon the nature of the vegetation — this be- 

 ing determined chiefly by climate, and modified by 

 variou's circumstances, having no connection with 

 the nature of the soil; but that soil has a very con- 

 siderable influence upon the quality of this vege- 

 tation, this influence depending more upon its de- 

 gree of fixedness, tenacity, and capability of im- 

 bibing and retaining moisture, than upon its chem- 

 ical properties." Chemical constitution, however^ 

 must excrcrse considerable power in dcermining" 

 the nature of the vegetation, as we have already 

 inlbrnied the reader, when explaining the charac- 

 ter and reliitionsof/wBim, that a soil depends very 

 much for the continuance of its dampness on the 

 quantity of decomposed vegetable and animal mat- 

 ters which it ma_v contain. Those most retentive 

 ofmoistiire, at ordinary seasons, owing to the close- 

 ness of their texture, are yet speedily deprived of it 

 on the accession of" warm weather, unless they con- 

 tain witfiin themselvps materials, from whose de- 

 composition water can always be produced, and, 

 therefore, such plants as afford a key to the quan- 

 tity of fluid in a soil, ma}-, Avith certain restrictions, 

 be looked upon as offering a means of guessing at 

 the nature of its constituents. In anotlier part of 

 his essay, Mr. Macgillivray thus expresses his 

 opinion on this subject: — "The great mass of 

 vegetation, or, a? it may be called, the standard 

 vegetation of the country, being diffused over 

 every sort of soil, sandy, grav^elly, gritty, clayey, 

 or vegetable, no. particular indications are afforded 

 by it of the nature of \\\e soil, unless with respect 

 to its luxuriance, which yet depends upon other 

 circumstances, more than upon tlie quality of the 

 soil. * * * With respect to luxuriance, the matter 

 is simply thus: Neither the chemical nor mechan- 

 ical nature of the soil influences the developement 

 of plants fiirther than as they contain the quantity 

 of moisture ftivorable to particular species or ge- 

 nera; and it can only be by a very complex view 

 of nature that one can attain a knowledge of the 

 suitableness of a soil for a particular species of 

 vegetable." 



"Some striking indications," continues Mr. 

 Macgillivray, "nevertheless, present themselves 

 to us in nature. Thus, if, while traversing an 

 extended heath, we observe at a distance a spot 

 covered with fresh verdure, we infer that the soil 

 there is certainly not peiit; and if, on approaching 

 it, we see pocB (meadoic grasses), vicitB (vetches), 

 and other plants, usually found in rich pasture, we 

 infer that the soil is vegetable, and so of other 

 soils. If, on the other hand, in a rich country, 

 we sec tracts, whether of hill or plain, covered 

 with a brown vegetation which we know to be 

 heath. \ve infer that the soil is peat. Still even 

 amoii;:,- these general appearances, there are few 

 that ti:i\c direct reference to soil. Thus, on see- 

 ing a long line of trees which we know, by their 

 physiognomy, to be alders or willows, we infer 

 that a river flows beside them; but we can make 

 no inference with respect to the soil. And thus, 



