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ground to the fineness of flour and is, therefore, much more expensive. 

 It is used somewhat extensively in some of the eastern states where the 

 farming practices are more intensive, but the Illinois theory is that the 

 coarser material used in larger quantity at the same total cost, will supply 

 somewhere near the same amount of fines for immediate availability and 

 will leave the coarser particles to gradually disintegrate and dissolve and 

 thereby furnish a "maintenance" ration over a longer period of time. 



What I referred to first ..as screenings, or what is sometimes called 

 "Limestone Dust," is a by-product from the prime product of crushed stone. 

 In reducing by crushing and in sizing by screening, the stone to meet the 

 requirements of the building trade as a concrete aggregate and of the 

 highway authorities for concrete and macadam roads and of the railroads 

 for ballast, it is necessary to eliminate by revolving screens all material 

 which runs one-quarter inch or less in size. Naturally, this eliminated 

 material varies in the proportion which it carries of the finer dust to the 

 coarser particles. This proportion is affected by such factors as the physi- 

 cal structure of the stone and the mechanical means used in its reduction. 

 In some states, especially where the stone is relatively hard, some of this 

 material is used as a top course for macadam roads, but generally speaking 

 that is not the case in Illinois. A limited amount is used for railroad 

 station yards and paths. Some of the fine powder is used as a filler in 

 cheap fertilizers, but much the greater percentage of this by-product must 

 be sold, just as it comes from the screen, for direct application to the 

 soil. As a by-product, it has been subject to the law of supply and demand 

 as applied to by-products and its selling price has been determined solely 

 by this law, without regard to a ratable portion of the cost of production. 

 The price of by-products is prone to move in the contrary direction to 

 the demand for and the price of the prime products from which they 

 come. When the demand for a certain prime product is great and the 

 price thereof mounts in consequence, there follows an increased production, 

 carrying with it an increase in production of the by-product, regardless 

 of the demand for the latter and if the demand for the by-product does 

 not simultaneously increase, at least in proportion, there follows a drop 

 in the by-product's price. The two prices thus moving away from each 

 other instead of in the same direction. 



Throughout the early years during which the use of limestone was being 

 advocated by the authorities and tried out by the farmers, the demand was 

 less than the unavoidable by-product supply. Under these conditions, it was 

 natural that many producers were willing to accept most any price that 

 would enable them to dispose of their output, and the consideration of an 

 equitable share of the total cost of production was not a factor. Taking 

 the state as a whole, it was not, perhaps, until 1918 or 1919 that the demand 

 for agricultural stone overtook and passed the production of by-product 

 screenings and it became necessary in order to meet the demand to resort 

 to the use of pulverizing machinery for the further reduction of sizes of 

 stone already marketable, as railroad ballast, concrete aggregate and road 

 stone; in other words, to resort to what I have referred to as the second 

 class of agricultural limestone, i. e.; directly pulverized material. This 

 meant that agricultural stone there and then passed from the realm of a 

 by-product into the realm of a prime product and the price instead of being 

 controlled by the consideration of moving a material that was in the way, 

 was controlled by the consideration of the cost of production, plus a profit. 



Obviously, the cost of producing agricultural stone, if it involves a fur- 

 ther processing of marketable commercial stone, is to that extent greater 

 than the cost of producing the commercial stone. Certain mischevious fac- 

 tors crept in at this point. First, it is not surprising, though it was un- 

 fortunate, that the price of the relatively small tonnage of directly pul- 

 verized material increased and controlled the price of the relatively large 

 tonnage of the by-product material. Second, the increased and rapidly in- 

 creasing demand, which made direct production necessary, encouraged, 

 whether or not it justified, the producers in decidedly marking up their 



