On the New Jersey Marls. 13 



It is necessary, however, that the dressings should be 

 repeated every ihree or four years. 



In the dry and sandy land of Monmouth, it is prized, 

 for potatoes, above stable manure. The quantity of the 

 crop is not so much increased by it, as its quality is im- 

 proved ; and the potatoes ripen several weeks sooner 

 than those brought forward in ihe ordinary way. Like 

 plaister, the operation of marl seems to be particularly 

 friendly to dry, hilly, and sandy soils ; and it is observed 

 to be remarkably active during warm and humid seasons. 

 Fields covered with it sparkle in the morning, after the 

 dews have evaporated from other grounds ; and, lastly, 

 like plaister, ferruginous marl is not to be regarded as a 

 direct manure, but rather as the agent that prepares for 

 plants the nourishment they find in the earth, or solicits 

 from the atmosphere. 



Although marl has been used with the happiest effect 

 on every species of vegetation that gypsum has been ob- 

 served to assist ; yet, in one important particular, the 

 operation of these minerals is essentially different. Marl 

 is scattered beneficially over wet swards, rough-bound 

 meadows, and cold clay soils — situations in which the 

 gypsum is altogether inert. Does not this fact tend to 

 prove that marl has a double operation, the one resulting 

 from its vitriolic acid, and the other from its proportion 

 of ferruginous matter ? 



GENERAL OBSERVATIONS, 



The use of ferruginous marl will form an epoch in the 

 agricultural memoirs of the State. From its activity, it 

 may be profitably carried to considerable distances. 



The use of ferruginous manures cannot be said to be 

 peculiar to the State of New Jersey. The residue of 

 martial pyrites after combustion, which is highly prized 

 I 



