WESTERN DISTRICT. 297 



Of the natural manures ok the wheat district. 

 Without doubt gypsum is the must important of those substances which are sometimi - 

 called mineral manures. I shall not, however, notice il in this place. It is confined to the 

 Wheat district : not a ton could be gathered elsewhere in the whole State. 



Next in importance to gypsum, is the shale of the Salt group, especially where it is 

 accessible. There are several kinds, and they all contain carbonate of lime and magnesia, 

 and organic matter, and, besides, are exceedingly decomposable under the ordinary atmo- 

 spheric influences. Some of them furnish a large amount of sulphate of soda, and the 

 deeper seated ones, the chloride of sodium in a free state, in addition to other chlorides 

 with which this substance is mixed, and which will be spoken of in the sequel. 



It can not be supposed that any of the mineral manures, except gypsum, are of suffi- 

 cient importance to be exported out of the district. They admit only of use when accessible 

 upon the estate, or the neighboring estates, where they are found: they are, however, 

 very important and valuable. 



The manures next in importance to the decomposing gypseous shales, are peat and 

 fresh water marl, or carbonate of lime which is found at the bottom of lakes and marshes in 

 a pulverulent form. Marl, however, is not always entirely pulverulent in this district : in 

 many places, it is assuming the condition of tufa ; but it may notwithstanding be regarded 

 as a valuable substance, suitable in itself as an enriching material, and also as a fertilizer 

 in virtue of its absorbent and retentive power for moisture. In this respect it ranks among 

 the first in value, taking place in absorbent qualities next to peat. 



There is a great supply of marl in all the central and western counties. It is impossible 

 to enumerate the localities. Most of the smaller lakes and ponds, and the bottoms of 

 marshes, throughout the whole district, contain it. 



The composition of tufa differs in no respect from that of marl ; in many tracts of land, 

 it may be more useful, when coarsely pulverized and spread over the soil, than mail, 

 inasmuch as it would both loosen a compact light soil, and furnish calcareous matter by 

 solution. It is equally rich in organic salts. As a source for supplying quicklime, it is 

 superior to any other form, and makes a beautiful white lime suitable for the finest works 

 required in building. 



Marl and tufa are composed mainly of calcareous matter, and, in composition, are much 

 the same from whatever source, or from whatever place it may be obtained. 



The following analysis of marl, from Christian hollow in Onondaga county, gives a fair 

 result, and shows how it is generally constituted : it differs but little from chalk in chemical 

 constitution. 



Water 22-2400 



Organic matter _ 0*5246 



Carbonate of lime 75*4554 



Peroxide of iron and alumina *6172 



Silica _. 0*5554 



Magnesia 0*6172 



| Agricultural Report. J 38 



