REPORT TO BOARD OF AGRICULTURE. 427 



jury from marling in the present crop (1839); so much diminished, 

 however, that its general average product this year [1842] is 

 fully twice as much as the land could have brought before being 

 marled. 



NOTE Y. 



DESCRIPTION AND ACCOUNT* OF THE DIFFERENT KINDS OF MARL, 

 AND OF THE GYPSEOUS EARTH, OF THE TIDE- WATER REGION OF 

 VIRGINIA. 



Report to tlie State Board of Agriculture, by Edmund Riiffm, 



Member and Corresponding Secretary of the Board, made in 



1842, and now corrected, altered, and enlarged. 



WITHIN the last twenty-five years there have been produced from 

 the application of calcareous manures more improvement and bene- 

 fit, both agricultural and general, in lower Virginia, than from 

 all other means and sources, numerous and valuable as have been 

 the agricultural improvements made. And for the latter half of 

 that time, no one agricultural subject has been treated of more at 

 length in the publications of this state. Still, there is much re- 

 quired to be known ; and it has very often, and not less so recently 

 than formerly, been required of the writer, who has furnished to 

 the press the larger part of all that has thence proceeded on this 

 subject, to give answers to inquiries, which, however variously 

 worded, amounted in substance to the question, " What is marl T' 

 or u Is my marl (or whatever earth was so termed) good marl, 

 and likely to be profitable as manure T' It has therefore appeared 

 to the writer that it would be useful to prepare something like a 

 natural history, or general and full description of the marls of low- 

 er Virginia ; and also of the kindred and yet very different mineral 

 manure, the gypseous earth, or "green-sand" earth, concerning 

 which latter so much error and delusion have been spread and long 

 maintained, and so little of truth or useful information derived from 

 the scientific sources generally respected as the highest authority. 



The main difficulty in the treating of this subject is presented in 

 the outset in the very term " marl," which is altogether misapplied 

 now in this country, though not so much as it has been, and per- 

 haps still is in England. Since this general course of misapplica- 

 tion was set forth by the writer at length in the " Essay on Calca- 

 reous Manures," there have become general in this country still 

 other misapplications of this always misapplied term. For' the 

 " green-sand" earth of New Jersey, which before had been called 



