Proceedings of the Farmers' Club. 605 



Mixed as such deposits must be witli clay and sand in degi'ees that 

 change with each locahty, these constituents vary ; but in many beds 

 the admixture of the clay and sand among the gunpowder grains is 

 very small, that is to say, it is possible for the Jersey farmer to get at 

 from two to eight cents a bushel, a marl that is nothing else than a 

 mass of these dark olive green gunpowder grains. Kow omitting 

 fractions, what does the farmer buy when he pays out money for this 

 curious green earth ? In a bushel weighing eighty pounds he gets of 

 potash soda about five pounds, of phosphoric acid about three pounds. 

 In 100 jDounds seventy -live are clay, sand and iron, ten are substances 

 of great value in agriculture, and fifteen are water and salts or acids 

 of little value, as magnesia. In pure green sand the quantity of lime 

 is small, often not much over a pound in a bushel. But green sand 

 is often found mixed with crumbling sea-shells. This shell marl is 

 rich carbonate of lime. 



How TO USE Marl. 



Suppose the farmer has a pile of this fertilizer in his yard, how is 

 he to get the most benefit from it ? Suppose there are 200 tons, an 

 ample top-dressing for a ten acre lot. In that 200 tons there are 

 20,000 pounds of a valuable alkali, and 12,000 pounds of an acid still 

 more precious. But they are both locked up in these little, round- 

 ish, olive-green granules, which, un crushed or undissolved, will do 

 vegetation no more good than so much mustard seed shot ; for be it 

 ever remembered, that roots and rootlets drink water, and water only. 

 If you would convey the acids and alkalies of manure, or of a rich 

 soil, into your crop, you can do it only by dissolving them in water. 

 The more dissolved potash, soda lime, and phosphate of lime and 

 silica you can get a plant to take up, the faster it will grow. The 

 chief complaint against marl is that it is not a prompt fertilizer ; it 

 does not show as much the first year as it does the second, and on 

 sandy soils its efiects are cpiite tardy. 



It is clear that we should do something to it to break down that 

 granular structure and release the powder within, so that water can 

 promptly dissolve it. The moisture and heat of the dung heap will 

 do it. Sulphuric acid will do it. So will quick-lime ; so would other 

 acids, such as the malic acid in apple pomace, and the woody acids 

 found in peat and swamp muck. Hence we recommend to farmers 

 to compost their marl with moist and sour substances. But when 

 green sand is spread on grass, there is a moist and sub-acid quality in 



