210 



I' A K M E 11 IS ' R E G 1 S T E li . 



[No. 4 



new productions. In this great rotation of Na- 

 ture's crop.?, the ag^es of man count but as years. 



Among these soils there are some, however, 

 more happily endowed. The natural rotation 

 then takes a different character: the larger plants 

 continue to live upon them; different characters of 

 thct^e plants only, arc replaced by others, and the 

 difl'erent families succeed each other. Thus on 

 good mountain soils we see the beech and the re- 

 sinous trees succeed each other in turn, as on good 

 soils in plains we see the birch replace the oak, 

 which soon reappears itself after one generation of 

 the birch. 



XXI. With this great analogy in all the princi 

 pal points which distinguish these soils, wilh their 

 identity of composition and of production, we still, 

 on each particular body of table land, or ridge, 

 (^plateau') meet wilh circumslanccs vv'hich appear 

 ])eculiar to each district, and Vv4iich it is perhaps 

 important to remark. Thus on the (Treat argilo- 

 silicious plateau of the basin of the Rhone, as it 

 rises towards the south and apprnaclmH l.yona, it 

 loses the name of Bresse to receive that of Dom- 

 bes; its soil becomes more sandy, ligliter, and less 

 wet, on a great extent of soil. In the most sandy 

 and least wet parts, one of the grasses, the anthox- 

 anlhum odoratum takes possession every year 

 among the rye, and covers the earth like a carpet. 

 Aller harvest it blooms, and its numerous heads 

 exhale a cadaverous odor which inlects the atmos- 

 phere. Some persons are inclined to regard this 

 odor as the principle of the endemic fever of the 

 country; but the fevers prevail where the soil is 

 not covered with the anthoxanthum. 



Is this anthoxanthum the same variety as that 

 of the botanists 7 The heads, the flowers and the 

 leaves have a great resemblance, the odor of the 

 two plants when bruised, is little different, the 

 smell of the flowers even has some suiiilarity: yet 

 there would be, apparently, good reason to doubt 

 their identity. The plant so called by botanists, 

 is one of the earliest blooming grasses in the 

 spring, and that of Dombes blooms at the end of 

 the summer: that of the botanists has an odor 

 which is in request to give a perfume to hay; its 

 stalks and leaves often rise above a foot; that of 

 Dombes only covers the soil, its flowers rise scarce- 

 ly 6 inches, and give out a smell almost intolera- 

 ble to those not habituated to it. Finally, that of 

 the botanists appears to be long-lived, while that 

 of Dombes can hardly be biennial, for it cannot 

 establish itself in the soil in the course of the year 

 preceding the rye during the fallow- ploughings; it 

 must spring up, at the earliest, in October, ^with 

 the rye itself, and last three months longer than it, 

 for at the end of October its plants are'' almost all 

 dry. 



If there are two different varieties, it would be 

 Elill uncertain whether the smell of that of Dom- 

 bes were natural to il, or arose from the climate 

 and soil which produced it. Could this soil, in 

 which the interior waters are corrupted at the time 

 of the flower's blooming, injure also the odor of 

 the plant? If the two plants belong to the same 

 variety, the question would be decided; the altera- 

 tion of odor would be owing to the state of the 

 soil at the end of summer. 



XXII. What particularly distinguishes the am-ilo- 

 eihcious soil from alluvial soils, and others of (7ood 

 nuality, is, that the sub-soil, which, as we have seen 

 does not difller from the upper straium, is entirely 



without vegetable matter, while we see in alluvial 

 soils, and even in calcareous soil^!, mould occurring 

 below the soil, or vegelablesurface stratum. Here, 

 there is only a barren clayey sand. Also, while in 

 other soils, vegetables sink their roots to seek nu- 

 tritive juice below — in this soil the roots run with- 

 out sinking, because there is nothing to be found 

 below the stratum exposed to the atmospheric in- 

 fluences. This circumstance explains, in a plausi- 

 ble manner, the quick exhaustion of the surface in 

 trees on white land, {terrain blanc) and conse- 

 quently their disappearance after a longer or shorter 

 period of vegetation. It is for this reason, that, 

 while in go'od soils trees often do little injury to 

 crops, and sometimes even afford ihcm advantage- 

 ous shelter; in the soil of which we speak, they 

 consume the resources of the surfiice, starve the 

 surrounding vegetables to some distance, and 

 wither them up, especially during the heats of 

 summer. It is thought suflicient to account 

 for this, to say, that "the shade burns.'''' Yet, 

 this ought to have quite a contrary effect, since it 

 evidently shelters from tlie beat of the sun. But 

 if we remark that this effect takes place in ail ex- 

 posures, that it is more sensible on the south side 

 of trees Vv^hcre the shade does not fall, than on the 

 north, which is often shaded, and that this eifcct 

 does not occur in deep soils into which the roots 

 descend, while it exercises all Its ravages on shal- 

 low soils, where the roots run far to draw from the 

 surface; if, lastly, we remark that the evil is much 

 greater during droughts, that it shows itself much 

 sooner on these points than elsewhere, that the 

 evil is seen in the withered leaves of the vegeta- 

 bles, and with all the sj'mptoms produced by 

 drought, we should necessaril}' conclude that this 

 effect is owing to the absorption of the humidity 

 of the soil and of some vegetable principles, by the 

 spreading roots of the tree at the expense of the 

 crop covering the soil. 



But a very conclusive fact confirms this expla- 

 nation, already so plausible. A row of poplars 

 planted on the edge of a field damaged the crops 

 very much. I caused a ditch to be dug so as to cut 

 the roots of the poplars; the following year, the 

 crop of wheat on one part, and of clover on the 

 other, Avas finer in that portion of the field which 

 the trees generally starved, than on all the rest of 

 the field. It must, therefore, have been the roots, 

 and not the shade, which injured the crops, and 

 the roots, therefore, absorbed the humidity much 

 sooner than they consumed the vegetable juices of 

 the soil. Yet, I would not admit that the nutri- 

 tive juices could have accumulated in the soil 

 which had to nourish, at the same time, the trees 

 and the crop; butl think that the decaying remains 

 of the roots, having become a vegetable nutri- 

 ment, gave the advantage to those portions of the 

 field which they formerly injured. 



XXIII. This kind of soil, it cannot be dissem- 

 bled, requires great intelligence and constant labor 

 to render productive. It is for this soil that the 

 proverb was made, "/«/(< vaut Vhomme, iant vaut 

 la terre,^^ (as man is, so is the earth;) but with 

 great care, much labor, and abundant manures, 

 (engrais) it may be raised to a jiroduction which 

 compensates the trouble and the outlay. 



What particularly distinguishes the argilo-sili- 

 ceous soil fi'om calcareous soils is, that in these 

 last, crofis without (alimentary) manure (fumier^ 

 grow, feebly it is true, but without appearing to 



