1836.] 



FARMERS' REGISTER. 



691 



sented in his essay on lime, of course attend this con- 

 tinuation. It is probable also(from the nature of things, 

 and not from any fault of the author,) that his state- 

 ments of the effects of marling are less to be relied on 

 for correctness, than those given by him of liming. For 

 both, he had to depend on the testimony and opinions 

 of other persons — and of course was liable to be mis- 

 informed: but this danger was much greater as to marl, 

 because the labors were more widely extended — in 

 some cases were of very ancient date — and generally 

 were executed by a class of farmers more ignorant, and 

 less observant, than those who are engaged in liming — 

 a business which requires, and usually engages, the at- 

 tention of more wealthy and intelligent farmers. We 

 have entire confidence in M. Puvis, when he states 

 facts on his own knowledge — but not in what he has 

 learned from others, especially when the supposed re- 

 sults are opposed to the theory which we believe to be 

 sound. 



Though the value of the following essay is not 

 equal to the author's first portion, on the use of lime, 

 and though, it is obnoxious to many charges of error, 

 still it is well worth the attention of every farmer who 

 desires to use calcareous manures of any kind. M. 

 Puvis is not guilty of the gross omissions, or errors on 

 the subject, which we have elsewhere charged on the 

 writers of Great Britain.* He does not like most of them, 

 leavehis readers in doubt as to the chemical composi- 

 tion of the manure he speaks of, nor of the soils on 

 which are they used; and, either directly or indirectly, we 

 can generally know what is the true nature of the ope- 

 ration, chemical or mechanical, of the marlings which 

 he describes. The quantities and the strength of the marl 

 applied, and the value of the effects produced, are sta- 

 ted much more fully and particularly than in any other 

 European work that has treated of calcareous manures. 

 These matters are of great value,as they will often enable 

 a reader to draw correct and useful conclusions, from 

 statements and opinions in which the author himself 

 may have been mistaken. 



We learn from M. Puvis that the earth which he cor- 

 rectly calls marl, is a deposite of fresh water. In that 

 respect as well as in others, it differs from what is called 

 marl in Lower Virginia — which in fact is the salt water 

 formation called crag in England, and falun in France, 

 and not called marl in either country. However, the 

 carbonate of lime contained, constitutes the value of 

 both, as manure — and the name is of no account, if 

 the composition and properties are properly understood. 

 But this difference is important in another point of 

 view. Valuable and extensive as are our beds of fossil 

 shells, (which in lower Virginia have usurped, and 

 monopolized the name of marl,) the formation is limi- 

 ted to the tide water region, or the space between the 

 Atlantic, and the falls of the rivers flowing intp it. But 

 the proper marl, as yet almost unknown to scientific 

 research, and altogether to practical use, may be found 



whether he is right, or not, as to this indication of the 

 presence of marl, it is certain that geology can furnish 

 sure guides to its position and extent, if indeed this 

 precise formation is to be found in this country. — Ed. 

 Farm. Reg. 



Composition, localities, and varieties of marl. 



Marl is a compound of carbonate of lime, and of 

 argil more or less mixed with sand. We have said 

 compound — we might perhaps have said combina- 

 tion, as that of alumine and silex in argil; for no 

 mechanical means, as suspension in water, will 

 serve to separate the carbonate of lime from the 

 argil. 



The formation of marl, in its many varieties, 

 would seem to have immediately preceded the 

 great argilo-silicious formation, which we believe 

 to have covered all the surface, and which, is found 

 every wdiere under different names: here, under 

 the name of white land [terrain blanc] there of 

 blanche terre; in the south, of boulbenne; in the 

 north, of terre clyire; and terre a boisj and in the 

 basin of the Loire, of the earth of Sologne.* 

 Almost everywhere, upon the borders of the pla- 

 teaux which these lands of the great alluvion pre- 

 sent, marl is met with in affleurmens; and under the 

 bed which forms these lands, it is found at greater 

 or less depth. Thus, in Sologne, under all its bor- 

 ders, and in the greater part of the basins which 

 furrow its surface — in Bresse, under the terrains 

 blancs — in the environs of Toulouse, under the 

 boulbennes — in Puisaye, under its white earth — and 

 in Normandy under its cold lands — marl is found, 

 as if placed by a benificent hand, to give to these 

 soils the activity and the means of producing, 

 which nature had not bestowed on them. 



Marl presents itself under many aspects, and in 

 many varieties, and compounded of very differ- 

 ent proportions. It is more or less rich, according 

 as it contains more or less carbonate of lime: its 

 consistence varies also according to this proportion: 

 it becomes harder as the quantity of carbonate of 

 lime increases up to 70 per cent., when it begins to 

 become stony. Over 80 per cent, it ceases to be 

 marl, belongs to a different formation, and is no 

 more found under the argilo-silicious bed: it crum- 

 bles with more difficulty, and becomes a marly 

 calcareous stone, good to make hydraulic lime, 

 but which slakes sometimes so badly, that it is 

 necessary to pound it, to make use of it as manure. 



Marls are met with in powder, which contain a 

 very large proportion of carbonate of lime: but 

 nature does not offer them commonly, but in banks 

 or deposites, [sacs] of little extent. 



It is remarked that the fertilizing power of marl 



* In a note to the Essay on the use of lime, (at p. 

 363, Vol. Ill, Farmers' Register,) we ventured to de- 

 scribe what were believed to be the peculiar characters 

 of the soil called by the author "argilo-silicious," and 

 in other regions, and may enable improvements by cal- known in different places under all the above provin- 



careous manures to be greatly extended and multiplied. 

 M. Puvis thinks that the marl formation will be regu- 

 larly found at some depth beneath the argilo-silicious 

 surface-soil, of such peculiar and base qualities. But 



*Soe Essay on Calcareous Manures, pp. 35, 82. 



1 names; and, though with only indirect evidence and 

 cclijecture for guides, we have since found that the 

 vflBrs then hazarded were correct. We have lately ob- 

 tained the numbers of the Annates for the year 1833 — 

 and there, among other pieces of M. Puvis, find a 

 more lull description of these ungrateful soils, con- 

 firming Fully our first impression. 



