ELLSIIA MITCHELL SCIENTIFIC SOCIETY. 13 



Fusion, ...... 10.14 per cent. 



Incineration and solution in IICA., . . . 10.09 " 



HNO3, . . 10.07 " 



Solution direct in HCl.-fKClOg, . . . 10.11 



HNO3 4- little HCI., . 9.56 " 



From tlio above it seems that in this case all the methods save 

 the nitric acid method were adequate, but it is not apprehended 

 that this will hold good in all cases. For, while here incinera- 

 tion and solution in nitric acid sufficed, there is certainly the 

 danger of imperfect solution already referred to; and while here 

 also solution in hydrochloric acid with [)otassium chlorate suf- 

 ficed, it has already been shown that this method failed to extract, 

 from the meal alone, more than lialf its content of phosphoric 

 acid„ Fusion is, of course, always adequate, but too time-con- 

 suming, if any other adequate method less so is at hand. It 

 seems probable that incineration and solution in hydrochloric 

 acid furnishes all that coidd be desired. 



It is in point to add that in this case the writer reported to 

 the manufacturers a total of 10.11 per cent., this being an aver- 

 age of the first four determinations. The insoluble found by 

 incineration and solution in hydrochloric acid was 1.47, making 

 an available of 8.64. It is not known what method the chemist 

 used to which the other half of this sample was sent, but his 

 total was 9.72, his insoluble 1.50 and his available^ therefore, 

 8.22. Note that the two insolubles are practically the same, and 

 that, therefore, his available is less than the writer's by practi- 

 cally the same amount that the writer's total is greater than his. 



Analytical Laboratory, 

 Raleigh, N. C. 



