12 JOURNAL OF THE 



such loss), or whether, as is much more likely, it was due to 

 imperfect solution of the ignited phosphate by nitric acid (a 

 danger already pointed out), is not positively shown. But it 

 should be remarked that in the case of 77, which is the case of 

 greatest disparity, the undissolved portions were manifest to tiie 

 eye, and it is the writer's conviction that had hydrochloric acid 

 been used instead of nitric, there would have been no material 

 difference in the results of the two methods, either in these par- 

 ticular determinations, or in anv other determinations. It is 

 regarded as certain, therefore, that there will be found no mate- 

 rial difference in the insoluble by which ever wav determined. 

 This being true, the available will vary directly and exactly as 

 the total; and, therefore, by just so much as a total is short on 

 account of the inadequacy of the nitric acid method when used 

 on cotton seed meal fertilizers, by just so much will the available 

 be short. 



Now a few words as to what method is adequate and a very 

 few experimental determinations on this point, and the subject 

 will for the present be laid aside. It is a matter of regret to 

 the writer that the time was not at his disposal for more extended 

 experimentation on the subject. Nevertheless he is none the less 

 convinced, on account of the limited number of experiments here 

 presented, of the truth of the point urged. 



In order to compare the total ns made by several different 

 methods sample 110 was chosen. This sample was sent by a 

 fertilizer company, who took a fair sample of a large lot of goods 

 at their factory, thoroughly mixed the sample and sent one-half 

 to the writer and one-half to a chemist in another State. The 

 total was determined first by fusing two grams of the fertilizer 

 with a mixture of equal parts of carbonate of soda and nitrate 

 of potash, as giving with certainty the maximum content, and 

 furnishing a standard for comparison. It was then determined 

 by incineration and solution in hydrochloric acid, by incineration 

 and solution in nitric acid, bv solution direct in hydrochloric 

 acid Nvith chlorate potash, and lastly, by solution direct in niti'ic 

 acid and a little hydrochloric acid. Following are the results: 



