CHARLESTON PHOSPHATE BEDS. 47 



Question. I would like to ask why one cow gives better 

 milk than another with the same food? 



Mr. Arnold. That is, perhaps, owing to the breed. 



Adjourned. 



SECOND DAY. 



The Board met at ten o'clock, and Hon. George B. Lor- 

 ing was called to the Chair. He announced the first subject 

 on the programme as a paper on 



THE PHOSPHATE BEDS OF THE CHARLESTON BASIN. 



BY CHARLES L. FLINT. 



Within the last half century, thousands of analyses have 

 been made in Europe and this country, of plants, of soils, of 

 fertilizers or substances which appear to constitute what may 

 be called the food of plants, till the laws of vegetable growth 

 are tolerably well understood. These analyses go to show, that 

 of the sixty-five elements which constitute the surface of our 

 globe, only a few are essential to plant-growth, but that these 

 are, within certain limits, absolutely indispensable, every 

 known plant being more or less dependent on them for its 

 sustenance. 



These elements, so essential to plant-growth, are carbon, 

 hydrogen, oxygen and nitrogen, derived either directly or 

 indirectly from the atmosphere ; and calcium, chlorine, iron, 

 magnesium, potassium, phosphorus, silicon, sodium and sul- 

 phur, derived from the soil. A few others may sometimes be 

 fouud in the composition of plants, but their presence seems 

 to be rather accidental than essential to the healthy growth of 

 vegetable life. The percentage in which these elements are 

 found in different plants may vary widely indeed, but this 

 difference is one of degree, and not of kind, since all plants 

 require these elements to be present in the soil in quantities 

 sufficient for their wants. 



But it is also true that some of these indispensable elements 

 are to be found in all soils in sufficient abundance, and that 

 only a few of them are removed in such quantities as to 

 require to be artificially supplied. Without entering minutely 



