FRIDAY MORNING SESSION. 



REPORT ON THE DETERMINATION OF NITROGEN. 

 I'.y I'IIAKI.KS L. PENNY, Referee. 



An a poll .-y i* due the association for failure to carry out the instructions of 1906 con- 



<( -n i i i ig t he permanganate im -t In > Is . A in >ther phase of the nitrogen question considered 



Li-i year ami di-cu<sed in correspondence with the National Fertilizer Association 



1 to i>uiwci-h in importance and urgency all others, namely, the determination 



of total nitrogen in mixed fertilizers to which nitrate of soda is added. With a view 



to making a thorough investigation of this subject, the following instructions were sent 



h members of thU association as WTC supposed to be interested in the work and 



to in. .re than I maly-i- nuiifd by the secretary of the National Fertilizer 



Association : 



INSTRUCTIONS. 



<'h<'tiii-i- < - >peratin'_: in this work are requested to ^ive t hoir attention exclusively 



to ni.-tli.-.l- applicable in the presence of nitrates. Mulletin 107, page 7 (c), page 8 (d), 



I (h). I here seema to be urgent need of this investigation, especially 



ih.- pn -iii iif-hods used to determine nitrate nitrogen have been formally 

 call.-d in question by the repreeentatiyee of great commercial interests. 



samples are sent h. -.- it is thought that each analyst, by calculating the 



nitrate u-ed from a volution of nitric acid carefully compared with his own standard 

 alkali and acid, may _;' more reliable results, through the balancing of possible errors, 

 than in -in u-inu' a common Mil.-ta-- 



t the .-i.urce ..f nitrate u-ed b> a solution of pure nitric acid, about fifth normal, 

 nio-t ie iirately tilrat.-d airain-i the -tandard alkali used in the Kjeldahl work. In 

 ea li case measure accurately into the digestion flask enough of this nitric acid to con- 

 tain :'.D to "><> niilligninis of nitr 



Follow in linu' the water in the nitric acid and without 



neiiirali/.ini;. 



l-'.-lloW likewise inetho.1 (d). 



(3) Follow met h< K! (g), adjust in-: the proper amount of water, distilling first with 



i.i. then with caustic >oda and water added to the residue in the distillation 

 Ma-k. collect ini: KffMinih- di.-i illaie< and titrating each separately. 



(4) Similarly follow method ih , beginning in second line "in a distillation flask," 



If the yield ,,f nitrogen is less than the calculated in (1), (2), (3), or (4), test the resi- 

 due in distillation Mask for nitr. 



- in (I), (2), (3), (-.) with the preliminary addition of 2 grams of cane 

 r to the digestion lla-k. 



U in U'. <-'. ( :i ), (4) with the preliminary addition of 1 gram, accu- 

 rutely u.-i-hed, ,,f -r-anic nitn^en substance, such as dried blood, fish scrap, or 

 tanka-e. to the di-.-ticn flask. In a separate operation treat 1 gram, accurately 

 weighed, Mt i hi- added .-ubstuiice similarly except that no nitrate be present; that is, 

 analy/e the added -ubsumce alone according to (c), (d), (g), and (h). Any nitrate- 

 free "mixed fertili/.er may be used for the added substance. 



While the above plan "entail- much work, it is hoped that a large number of chemists 

 will ted 1 1 1,-ast some of the several official methods in question, if not all. Ihe figures 

 for each separate determination should be reported and the precise method pursued 

 should be fully explained. The results of any other plan of studying the nitrate ques- 

 tion, rarried mt by chemists at their own suggestion, will be welcomed. 



(85) 



