190 CALCAREOUS MANURES— APPENDIX. 



Yet it is remarkable, that Marshall should not have intimated whether 

 the Norfolk soils were naturally calcareous, (as the two writers just before 

 quoted declare,) or not ; and therefore we are still left to guess whether 

 these manures served to increase tlie calcareous quality of soils already 

 possessing that quality in a high degree— or to give it to soils devoid of it 

 before. 



Other passages will now be quoted from the same, and from other similar 

 works of Marshall's, to show the prevailing ignorance of the ingredients, 

 and operation of the marls sometimes prized, and sometimes contemned, 

 with as little reason in the one case as the other, by farmers in various 

 parts of England. 



25. " The principal part of his estate, however, is of a much shallower soil, not deeper 

 than the plough goes ; and its present very amazing fertility he ascribes in a great mea- 

 sure to his having clayed it. Indeed to this species of improvement the fertility of the 

 Fleg Hundred is allowed to be principally owing. 



" Mr. F. gave me an opportunity of examining his clay pit, which is very commodi- 

 ous ; the uncallow is trifling, and the depth of the bed or jam he has not been able to 

 ascertain. It is worked, at present, about ten or twelve feet deep. 



" The color of the fossil, when moist, is dark brown, interspersed with specks of white, 

 and dries to a color lighter than that of fuller's earth ; on being exposed to the air, it 

 breaks into small die-like pieces. 



" From Mr. F's. account of the manner of its acting, and more particularly from its 

 appearance, I judged it to be a brown marl, rather than a clay ; and, on trying it in acid, 

 it proves to be strongly calcareous ; effervescing, and hissing, more violently than most 

 of the white marls of this neighborhood : and what is still more interesting, the Hemsby 

 clay is equally turbulent in acid as the Norwich marl, which is brought by water forty 

 miles into this country, at the excessive expense of four shillings a load upon the staith ; 

 firesides the land carriage. [The strength of this Hemsby clay is stated above.] 



" It is somewhat extraordinary that Mr. F., sensible and intelligent as he is, should be 

 entirely unacquainted with this quality of his clay ; a circumstance, however, the less 

 to be wondered at, as the Norfolk farmers, in general, are equally uninformed of the na- 

 ture and properties of marl." — MarshalVs No)Jvlk, vol. ii., page 192. 



The following is a remarkable instance, in a particular district, of a clay 

 very poor in calcareous matter, being considered and used as valuable ma- 

 nure, and a very rich marl equally accessible, being deemed inferior. 



26. " The marl is either an adulterate chalk, found near the foot of the chalky steeps 

 of the West Downs, lying between the clialk rocic and the Maam soil, partaking of 

 them both — in truth, a marl of the first quality, or a sort of blue mud, or clay, dug out 

 of the area of this district, particularly, I believe, on the south side of the river. This 

 is said to have been set on with good effect ; while the former is spoken of, as of less 

 value; whereas, the white is more than three-fourths of it calcareous-, while the blue 

 does not coatain ten grains, per cent., of calcareous matter." — MarshalVs Southern Coun- 

 ties, p. 175. 



The greater part of what are called marls in the following extract, and 

 used as manure, contain so little calcareous earth, that whatever power 

 they may exert, niust be owing to some other ingredient. Yet, without 

 Marshall's analysis, they would be considered to deserve the character of 

 calcareous manures, as much as any others before named. 



27. " The red earth which has been set upon the lands of this district, in great abun- 

 dance, as ' marl,' — is much of it in a manner destitute of calcareous matter ; and, of 

 course, cansot, with propriety, be classed among marls. 



" Nevertheless, a red fossil is found, in some parts of the district, which contains a 

 proportion of calcareous matter. 



" The marl of Croxall (in part of a stone-like, or slaty contexture, and of a light red 

 color) is the richest in calcareosity ; one hundred grains of it afford thirty grains of cal- 

 careous matter ; and seventy grains of fine, impalpable, red-bark-like powder.* 



* This marl is singularly tenacious of its calcareous matter ; dissolving remarkably 

 slowly. One hundred grains, roughly pounded, was twenty-four hours in dissolving ; 



