19 



fVood Ashes. Thirty-eipht carloads of wood ashes were anal- j] 



yzed, representing nine different brands. The average of these anal- J 



yses shows moisture 20.91 per cent; phosphoric acid 1.3.5 per cent; '„ 



calcium oxide 29.46 per cent; total or acid soluble potash 3.81 per J 

 cent; water soluble potash 2.84 per cent. The above average shows 



that about 74.5 per cent of the total potash was soluble in water, 1^ 



as against 77.75 per cent for the previous year. Several samples \ 



recently analyzed, but which do not appear in the tables of analysis J 



in this bulletin, have shown a very low water soluble potash test, ' 



as compared co the acid soluble test. These samples have been I 



studied to determine if they had received an addition of granite or t 



feldspar, but no indications of such an admixture were apparent, ' 



and it is probable that the large amount of water insoluble , 



potash is due to the high temperature at which the ashes were made, i 



which would result in the fusion of a larger portion of the potash 1 



with silica compounds present. Wood ashes have cost on the av- \ 



erage $14.80 per ton. Allowing a fair value for the lime and phos- • 



phoric acid present in the average ash of good quality, makes wood I 



ashes, under the present conditions, the cheapest source of potash. • 



Phosphoric Acid Compounds. Acid phosphate has, to a greater 

 extent than ever before, furnished the larger proportion of the avail- 

 able phosphoric acid used in agriculture. A small amount of pre- 

 cipitated phosphate, basic lime phosphate, and American slag have 

 been offered, and representative samples of all of these compounds 

 have been collected and analyzed. 



Acid Phosphate. Thirty-nine samples of acid phosphate have 

 been examined, necessitating twenty-one analyses. . No serious de- 

 ficiencies were found. The average per cent of available phosphoric 

 acid found was 16.32. Acid phosphate has cost, on the average, 

 $20.94 per ton, making the pound of available phosphoric acid from 

 this source cost 6.42 cents. 



Basic Slag Phosphate. Only one brand of genuine basic slag 

 phosphate was registered this season, — a domestic product manu- 

 factured by the Tennessee Coal, Iron & Railroad Co., of Birming- 

 ham, Ala. Two samples of this product were analyzed, showing 

 an average of 17.75 per cent available phosphoric acid. 



Basic Lime Phosphate. Three samples, representing three 

 distinct brands, have been analyzed. Two of these showed a small 

 shortage in available phosphoric acid, but over-runs in total. The 

 average available phosphoric acid has been 12.97 per cent. The 

 average ton cost has been $22.50, making the pound cost of available 

 phosphoric acid 8.77 cents. 



