392 MARSHALL'S STATEMENTS. 



who have used calcareous manures longest and most extensively, 

 although without knowing what they were doing. 



In his li Rural Economy of Norfolk " the "marls" and "clays" 

 most used in the celebrated improvements of that county are mi- 

 nutely described, and the chemical composition stated, showing that 

 both are highly calcareous. Of the " marls" or chalks, most used 

 for manure in Norfolk, he analyzed three specimens, and one of 

 clay, and found the proportions of pure calcareous matter as 

 follows : 



Chalk marl of Thorp-market, contained, per cent. . . 85 

 Soft chalk of Thorp-next-Norwich, . . . .98 



Hard chalk of Swaffham, almost pure, nearly . . 100 

 Clay marl of Hemsby ....... 43 



37. Of these he spoke previously and in general terms, thus : 

 "The central and northern parts of the district abound, universally, with 

 a whitish-coloured chalk marl ; while the Fleg hundreds, and the eastern 

 coast, are equally fortunate in a gray-coloured clay marl. The first has, 

 in all probability, been in use as a manure many centuries ; there are oaks 

 of considerable size now going to decay in pits which have obviously been 

 heretofore in use, and which, perhaps, still remain in use, as marl-pits. 



" The use of clay marl, as a manure, seems to be a much later discovery; 

 even yet, there are farmers who are blind to its good effect ; because it is 

 not marl, but "clay;" by which name it is universally known. The name, 

 however, would be a thing of no import, were it not indiscriminately ap- 

 plied to unctuous earths in general, whether they contain, or not, any por- 

 tion of calcareous matter. Nothing is "marl" which is not white ; for, 

 notwithstanding the county has been so long and so largely indebted to its 

 fertilizing quality, her husbandmen, even in this enlightened age, remain 

 totally ignorant of its distinguishing properties ; through which want of 

 information much labour and expense is frequently thrown away. One 

 man, seeing the good effect of the Fleg clay, for instance, concludes that 

 all clays are fertile, and finding a bed of strong brick earth upon his farm, 

 falls to work, at a great expense, to "claying" while another, observing 

 this man's miscarriage, concludes that, all clays are unprofitable ; and, in 

 consequence, is at an expense, equally ill applied, of fetching "marl" from 

 a great distance ; while he has, perhaps, in his own farm, if judiciously 

 sought after, an earth of a quality equally fertilizing with that he is throw- 

 ing away his time and his money in fetching. Marshall's Norfolk, vol. i., 

 p. 16. 



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 the 

 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. 



