CALCAREOUS CLAYS OP NEW YORK. 391 



to lessen rather than to increase the previous calcareous constitu- 

 tion of the soil. 



36. In connexion with this statement of the poor "clay marls" of 

 Britain, it is worthy of notice that of six kinds of " clay" (not 

 " clay marls," but presented simply as clays), of New York, ana- 

 lyzed and reported by Professor Emmons (and quoted in Browne's 

 Muck Book), the calcareous proportion in five was either nearly as 

 large, or larger, than in the above stated British " clay marl." The 

 specimens reported by Professor Emmons were as follows : 

 "Tertiary or Albany clay, contains carbonate of lime per cent. . 8.00 

 Niagara clay .......... 14.62 



Cayu|a clay . 16.48 



Adoniracli clay . . . . . . . . . .0.94 



Brick (?) clay, near Caldwell 8.92 



Reddish clay of Christian Hollow 8.29" 



Browne's Muck Book (1852). 



All but one of these New York "clays" would be "clay marls" 

 in Britain, according to Stephens, the latest and a high British 

 authority. 



Most of the extracts which I have presented, are from British 

 agriculturists of high character and authority. If such writers as 

 these, while giving long and (in some respects) minute statements 

 of marl and marling, omit to tell, or leave their readers to doubt, 

 whether the manure or the soil is the most calcareous or what 

 proportion of calcareous earth, or whether any is present in 

 either then have I fully established that the American reader 

 who may attempt to draw instruction from such sources, as to the 

 operation, effects, and profits of either marl or calcareous manures 

 in general, will be more apt to be deceived and misled than 

 enlightened. 



I have now to refer to an author, whose works, well known as 

 they may be to others, had not come under my view until after the 

 earliest publication of most of the foregoing extracts. Otherwise, 

 Marshall would have been stated as an exception to the general 

 silence of British authors as to the true and precise nature of what 

 they treated of as marl. But though he has not been, like others, 

 so famlty as to leave in doubt what was the character and value of 

 the marls of which he spoke, and the nature of their operation on 

 the soils to which they were applied, still no other writer furnishes 

 stronger proof of the general ignorance and disregard of the nature 

 of marls and calcareous manures, and of their mode of operation ; 

 and even the author himself is not free from the same charge, as 

 will be shown. I shall quote the more at length from Marshall, 

 because he presents the strongest opposition to what I have stated 

 as to the general purport of publications on marling ; and also, 

 because whatever may be their character, there is much to interest 

 the reader in his accounts of the opinions and practices of those 



