88 ECONOMICAL MINERALOGY. 



fertilizing agent. Its composition is similar to that of the water limestone so abundant in this 

 county, and with which it is no doubt associated. An analysis gave the following results : 



Carbonate of lime, 29.45 



Carbonate of magnesia, 24-30 



Silica and alumina, 42. 50 



Oxide of iron, 3. 75 



This limestone contains cubical and dodecahedral crystals of iron pyrites, similar to those 

 found in the county of Schoharie. 



Warren County. The northern parts of the State are known to be less abundantly sup- 

 plied with marl tlian the southern or western parts. They contain, however, a few localities 

 of this kind. And in addition to those already noticed, we have an extensive deposit in the 

 to^vn of Queensbury in this county, on lands owned by Mr. Jenkins, and there are several 

 smaller ones in that vicinity ; the marl lieing generally associated with peat. 



In Washington County, a white and friable marl, resembling the whiting of commerce, 

 has been found. 



Wayne County. A white and earthy marl, containing abundance of shells, is found under- 

 lying the Cayuga marslics in the town of Savannali. Again, along the Erie canal, near New- 

 ark, is a deposit of a similar kind, but of no great depth. Another occurs at Cooper's swamp, 

 in the south part of tiie town of Williamson ; while of the gypseous marl, or the mixture of 

 marl and gypsum, there are several localities in this county. 



From the preceding facts, it is evident that the State of New-York is abundantly supplied 

 with the mineral just noticed. Other localities will undoubtedly be added to the list, as soon 

 as its great value for the purposes of agriculture come to be properly understood. It is well 

 known, tliat in some parts of the United States, marl has been used with the most beneficial 

 results. It should be remarked, however, that tiiis term is often widely applied to include 

 almost all fertilizing agents applied to the soil. Thus the New-Jersey marls, wliich have 

 effected such an astonishing change in the agricultural condition of that State, belong to what 

 is called the "green sand" formation, and contain but a small proportion of carbonate of lime, 

 which predominates in ahnost all the New- York marls. It is supposed that the potash is the 

 chief fertilizing ingredient in the New-Jersey marls; while there can be no doubt that carbo- 

 nate of lime is the constituent whicli gives to the shell marls, to which those of New-York 

 principally belong, their value. 



It may be added, on the authority of a standard author on tliis subject, that shell marl may 

 be used at the rate of from twenty to thirty cart loads to the acre ; while of the clay marl, a 

 much larger amount may be employed. These proportions, however, must depend in a great 

 measure upon the nature of the soil to which it is to be applied.* 



* Chaptal. Chemistry apjjUed to Agriculture. Amer. Ed. 44. 



