CALCAREOUS MANURES— APPENDIX. JQ] 



" And a marl of Elford (in color and contexture various, but resembling those of tlie 

 Croxall marl) affords near twenty grains. 



" Yet the marl of Barton, on the opposite side of the Trent — though somewhat of a 

 similar contexture, but of a darker more dusky color — is in a manner destitute of calca- 

 reosity ! one hundred grains of it yielding little more than one grain — not two grains of 

 calcareous matter. Neverthless, the pit, from ^'hich I took the specimens analyzed, is 

 an immense excavation, out of which many thousand loads have been taken. 



" And the marls of this neighborhood (which mostly differ in appearance from those 

 described, having generally that of a blood-red clay, interlayered, and sometimes inter- 

 mingled with a white gritty substance) are equally poor in calcareosity. 



One hundred grains of the marl of Stafford (which I believe may be taken as a fair 

 specimen of the red clays of this quarter of the district) afford liltle more than two grains 

 of calcareous matter.* Yet this is said to be 'famous marl;' and from the pits which 

 now appear, has been laid on in great abundance. 



"I do not mean to intimate, that these clays are altogether destitute of fertilizing 

 properties, on their first application. It is not likely that the large pits which abound 

 in almost every part of the district, and which must have been formed at a very great 

 expense, should have been dug, without their contents being productive of some evi- 

 dently, or at least apparently good effect, on the lands on which they have been spread. 



I confess, however, that this is but conjecture ; and it may be, that the good effect 

 of the marls, first described being experienced, the fashio7i was set; and the distinguish- 

 ing quality being unknown, or not attended to, marls and clays were indiscriminately 

 used." — Marshall's Midland Counties, vol. i. p. 152. 



28. " On the southern banks of the Anker, is found a gray marl ; resembling in gene- 

 ral appearance the marl of Norfolk, or rather the fuller's earth of Surrey. In contexture 

 it is loose and friable. 



" This earth is singularly prodigal of its calcareosity. The acid being dropped on its 

 surface, it flies into bubbles as the Norfolk marl. This circumstance, added to that of 

 a striking improvement, which I was shown as being effected by this earth, led me to 

 imagine that it was of a quality similar to the maris of Norfolk. 



"But, from the results of two experiments — one of them made with granules formed 

 by the weather, and collected on the site of improvement, the other with a specimen 

 taken from the pit, it appears that one hundred grains of this earth contain no more than 

 six grains of calcareous matter ! the residuum a cream colored saponaceous clay, with 

 a small proportion of coarse sand." — Marshall's Midland Counties, vol. i. p. 155. 



The last extracts suggested a remark which ought to have been made 

 earlier. When there is so much general ignorance prevailing among prac- 

 tical farmers as to what they call marl, it cannot be expected that the most 

 intelligent writers can be correct, when attempting to record their prac- 

 tices. When Arthur Young, for example, reports the effects of marl in 

 fifty different localities, as known from the practice of perhaps more than 

 several hundred individuals, it must be inferred that he uses the term, 

 generally, as they did from whom his information was gathered, and in 

 very few cases, if at all, as learned by his own analyses. Therefore, it 

 may well be doubted whether the uncertainty as to the character of marl 

 does not extend very generally to even the most scientific writers on agri- 

 culture. 



As the foregoing extract exhibits the use of " marls" destitute of calca- 

 reous earth, so the following shows, under the name of sea sand, a manure 

 which is in its chemical qualities a rich mai'l (in our sense) or calcareous 

 manure. 



29. " Sea sand. This has been a manure of the district, beyond memory or tradition. 

 "There are two species still in use: the one bearing the ordinary appearances of 

 sea sand, as found at the mouths of rivers ; namely a compound of the common sand 

 and mud; the other appears to the eye clean fragments of broken shells without mix- 

 ture ; resembling in color and particles, clean-dressed bran of wheat. 



and another hundred, though pulverized to mere dust, continued to effervesce twelve 

 hours ; notwithstanding it was first saturated with water, and afterward shook repeat- 

 edly. The Breedon stone, roughly pounded, dissolved in half the time ; notwithstanding 

 its extreme hardness. 

 * Lodged not in the substance of the clay, but in its natural cracks or fissures. 



