186 CALCAREOUS MANURES- APPENDIX. 



fifty different parishes, neighboriioods, or separate farms. Among all tiiese, 

 the only statements from which the calcareous nature of the manure may 

 be gathered, are, (page 406,) of a marl that " ferments strongly with acids" 

 — another, (page 409,) that marling at a particular place destroys sorrel — 

 and (page 410) that the marl is generally calcareous, and that that contain- 

 ing the most clay, and the least calcareous earth, is preferred by most per- 

 sons, but not by all. 



13. Young's General View of the Agriculture of Suffolk, (an octavo of 432 

 pages of close print,) in the description of soils, affords no information 

 as to any of them being calcareous, or otherwise ; yet the author mentions 

 (page 3) having analyzed some of the soils, and reports their aluminous 

 and silicious ingredients. Nor can more be learned in this respect, in the 

 long account afterwards given of the " marl" which has been very exten- 

 sively applied also in the county of Suffolk. We may gather however, 

 from the following extracts, that the " marl or clay" of Suffolk is generally 

 calcareous, but that this quality is not considered the principal cause of its 

 value ; and further, that crag, a much richer calcareous manure, (which 

 seems to be the same with our richest beds of fossil shells, or marl,) is 

 held to be injurious to the sandy soils, which are so generally improved by 

 what is there called marl. 



" Claying — a term in Suffolk, which includes marling ; and indeed the earth car- 

 ried under this terra is very generally a clay marl ; though a pure, or nearly a pure clay, 

 is preferred for very loose sands." — Young's Suffolk, p. 1S6. 



14. After speaking of the great value of this manure on light lands, he 

 adds 



" But when the clay is not of a good sort, that is, when there is really none, or scarcely 

 any clay in it, but is an imperfect and even a hard chailc, there are great doubts how far 

 it answers and in some cases has been spread to little profit." — p. 187. 



15. " Part of the under stratum of the county is a singular body of cockle and other 

 shells, found in great masses in various parts of the country, from Dunwich quite to the 

 river Orwell, See." — " I have seen pits of it to the depth of fifteen or twenty feet, from 

 which great quantities had been taken for the purpose of improving the heaths. It is 

 both red and white, and the shells so broken as to resemble sand. On lands long in 

 tillage, the use is discontinued, as it is found to make the sands blow more." [That is, to be 

 moved by the winds.] — p. 5. 



1 5. The Essay on Manures, by Arthur Young, for which the author was 

 honored with the Bedford medal, speaks distinctly enough of the value of 

 marl being due to its calcareous ingredient, (as this author doubtless always 

 knew, notwithstanding the looseness of most of his remarks on this head—) 

 but at the same time he furnishes some of the strongest examples of absurd 

 inferences, or of gross ignorance of the mode in which calcareous earth 

 acts as an ingredient of soil, and the proportion which soils ought to 

 contain. These are his statements, and his reasoning thereon : 



" It is extremely difficult to discover, from the knowledge at present possessed by the 

 public, what ought to be the quantity of calcareous earth in a soil. The best specimen 

 analyzed by Giobert had 6 per cent. ; by Bergman, 30 per cent. ; by Dr. Fordyce, 2 per 

 cent.; a rich soil, quoted by Mr. Davy, in his lecture at the Royal Institution, 11 per 

 cent. This is an inquiry, concerning which I have made many experiments, and on soils 

 of the most extraordinary fertility. In one, the proportion was equal to 9 percent.; in 

 another 20 per cent. ; another, 3 per cent. ; and in a specimen of famous land, which I 

 procured from Flanders, 17 per cent. But the circumstance which much perplexes the 

 inquiry is, that many poor soils possess the same or nearly the same proportions as the^^e 

 most fertile ones. To attain the truth, in so important a point, induced me to repeat many 

 trials, and to compare every circumstance ; and I am disposed to conclude, Ihat the neces- 

 sity of there being a large proportion of calcareous earth in a soil depends on the deficiency 

 of organic [i e. vegetable or animal] matter ; of that organic matter which is [partly] 



