8 JOURNAL OF THE 



dissolved in acid, and a percentage of 3.24 of total phosphoric 

 acid found; a duplicate in the same manner yielded 3.20, though 

 in this case tlie incineration was not quite so perfect, a little char 

 being left. The true per cent, of total phosphoric acid in the 

 meal then was 3.24. A solution of two grams made by hydro- 

 chloric acid with chlorate of potash also failed by something 

 more than half of getting the full amount. This yielded 1.45 

 per cent. Next two grams of the meal were taken, washed with 

 cold water in exactly the same manner as when extracting the 

 soluble phosphoric acid from an ordinary fertilizer, then digested 

 with citrate solution and again washed exactly as is done in the 

 determination of insoluble phosphoric acid. The residue was 

 ignited and the phosphoric* acid determined. It was found to be 

 0.24 per cent. So not only did a cotton seed meal which showed 

 only half a per cent, of total phosphoric acid to a nitric acid 

 solution contain in reality three and a quarter i)er cent., but three 

 per cent, of this three and a quarter per cent, was available by 

 the methods of analysis. 



A cotton seed meal fertilizer may easily contain one-third 

 cotton seed meal, and, if the meal had the com])()sition of that 

 examined above, would owe one per cent, of its available phos- 

 j)lioric acid to the meal. If, therefore, such a fertilizer were to 

 be analvzed by the nitric acid method, it would theoretically 

 show a shortage of nearly one per cent, of available phosphoric 

 acid (0.90 exactly). While none of the experiments herein given 

 exhibit as great a disparity as this, some approximate it, and it 

 is believed that a disparity fully equal to this is quite possible. 

 Whether the entire disparity is always due to the retention of 

 the phosphoric acid of the meal alone, or whether in some cases 

 the meal, while holding some of the ph()s})lioric acid of the 

 phosphate in check, gives up more of its own, or whether, in 

 other cases, the phosphoric acid of the phosphate in })recipitating 

 carries more of the UJcaTs phosphoric acid down with it than 

 would otherwise go and thus lessens the disparity, is not clear. 

 I am inclined to think that new and fresh meal will exhibit this 

 peculiarity in a greater degree than old meal, though of that I 



