Table II. Some criticism, however, seems called for in connection with the 

 degree of fineness to wliich at least four of the products were ground : these were 

 manufactured by the Hoosac Valley Lime Co., Inc., D. U. Smith & Bro., Hazen 

 Brothers, and Eastern States Farmers' Exchange. We should not lose sight of 

 the fact that the fineness of any ground limestone or ground shell lime determines 

 in no small measure its effectiveness in neutralizing soil acidity during a one- 

 or two-year period. This is of particular significance when, as is sometimes 

 the case, the handling and transportation charges equal or exceed the original 

 cost of the product at the plant. 



The inspection of ground limestone products shows that in some instances 

 refuse burned lime known as "core" has been added. This in no way lessens 

 the value of the product, but on the contrary increases the neutralizing value 

 and should not add seriously to the discomfort of handling. 



Explanation of Tables of Analyses. 



Table I, "Proportion of total oxides as carbonates." The data furnished in 

 this column are calculated from an actual determination of carbon dioxide 

 (CO2). Calcium or magnesium not in the form of carbonate is present either as 

 hydrated lime (water- or air-slaked), burned lime (caustic or unslaked), or as 

 basic silicate. It should be understood that all of the products listed in this 

 table have at some time been burned, and the proportion of oxides present as 

 carbonates indicates to what extent the product has absorbed carbonic acid 

 from the air. 



"Neutralizing value expressed in terms of calcium oxide" represents the acid 

 neutralizing value of both the magnesium and calcium. The figures in the " per 

 cent" column are obtained by a direct titration with standard acid. The 

 "pounds in one ton" are secured by multiplying the figures in the "per cent" 

 column by 20. 



Table II, in the column headed "Carbonates of calcium and magnesium" 

 the calculation allows for the small amounts of calcium and magnesium combined 

 as basic silicates; these are readily soluble in mineral acid solutions but obviously 

 should not lie classed as carbonates. 



"Neutralizing value: per cent and pounds in one ton." In securing these 

 data the degree of fineness to which the limestone has been ground is taken into 

 consideration. When the products are so finely ground that all of the material 

 will pass through a 20-mesh sieve, it is assumed that all of the calcium and 

 magnesium oxides will become available in the soil within a five-year period. 

 In the less finely ground products it is assumed that the oxides in that portion 

 which is coarser than 20-mesh will be only 50 per cent effective during the same 

 period. 



Under "Mechanical analysis" the figures represent in round numbers the 

 percentage of product that would pass the various meshed sieves mentioned. 



In both tables the figures in parentheses following the brand name show the 

 number of samples collected and analyzed. 



