"THIRD DAY. 



SATURDAY MORNING CESSION. 



Mr. J. P. Street introduced a resolution approving national legis- 

 lation regulating the composition and sale of insecticides and fungi- 

 cides. The matter was referred to the committee on resolutions. 

 (See page 189.) 



REPORT ON PHOSPHORIC ACID. 

 By J. M. MCCANDLESS, Referee. 



On May 19, 1908, the referee sent out a letter to twenty-one chemists, quoting the 

 recommendations made by the association, as follows: 



(1) That the referee on phosphoric acid take up for report at the next meeting of 

 the association methods applicable under American conditions to the official exami- 

 nation of basic slag phosphates. 



(2) That the subject of an accurate determination of iron oxid and alumina in rock 

 phosphates be examined by the referee on phosphoric acid and an official method be 

 recommended to the association next year. 



(3) That a number of chemists be requested to send to the referee on phosphoric 

 acid samples of the citrate ammonia solution employed by them, and that the referee 

 examine such samples as to neutrality and that such examination be reported to the 

 chemists at the next annual meeting. 



In compliance with these instructions the referee requested those who desired to 

 cooperate in the work to send him a bottle (200 cc) of their solution of ammonium 

 citrate and a short statement of the method used in making the samples neutral. 



In response to this letter the referee received nine samples of ammonium citrate 

 solution for examination and forwarded to ten chemists three samples each, one of 

 pulverized brown Tennessee rock, one of pulverized Florida rock, and one of a syn- 

 thetic solution made from microcosmic salt, recrystallized potash-alum, ferrous 

 ammonium sulphate, calcium carbonate, magnesium sulphate, and calcium fluorid, 

 so that 100 cc would represent 1 gram of substance, and on that basis the solution 

 should contain exactly 3 per cent of ferric oxid and 2 per cent of alumina. 



A letter of instructions was forwarded with the samples requesting that the coopera- 

 tors test the following methods for iron and alumina, it being deemed best to restrict 

 the work to these phases' 



METHODS FOR THE DETERMINATION OF IRON AND ALUMINA IN PHOSPHATE ROCK. 



It is recommended that before beginning the work each analyst make up for him- 

 self a synthetic solution from C. P. chemicals, containing 10 grams of microcosmic 

 salt, 10.4 grams of calcium carbonate, 0.050 gram of magnesium oxid or its equivalent 

 in magnesium sulphate, 0.300 gram calcium fluorid. To these should be added 

 accurately known weights of C. P. crystallized potash, or ammonia alum, and ferrous 

 ammonium sulphate or iron wire. The material should be dissolved in hydrochloric 

 acid and water and made up to a liter. The methods should be tried upon this solu- 

 tion to acquire confidence and applied to the referee's samples, using the following 

 methods: 



(140) 



