92 



At the close of the reading of the nitrogen report, the president 

 announced the following committees: 



Committee on amendments to the constitution: J. P. Street, J. T. 

 Willard, P. F. Trowbridge. 



Committee on nominations: R-. J. Davidson, C. H. Jones, B. B. 

 Ross. 



Committee on resolutions: L. L. Van^Slyke, A. J. Patten, V. K. 

 Chestnut. 



REPORT ON INORGANIC PLANT CONSTITUENTS. 

 By H. D. HASKINS, Referee. 



The work on inorganic plant constituents has been along lines recommended by 

 the referee of the preceding year, particularly with reference to the development 

 of a method for the determination of iron and aluminum in ash. The sample which 

 has served for the work was prepared by thoroughly mixing the ash of a species of 

 Lycopodium, known to contain a large proportion of aluminum, with a finely ground 

 and incinerated sample of wood ashes, the latter being known to contain considerable 

 quantities of iron. 



PROPOSED METHODS. 



The method proposed for study contains some of the features incorporated in the 

 official method of determining ferric and aluminic oxids and phosphates in .soils 

 (Bui. 107, p. 15). See also Bui. 56, Proceedings of the Fifteenth Annual Convention 

 of the association in which recommendations are made by Ilartwell in regard to a 

 method described in Crooke's Select Methods of Chemical Analysis. The method 

 as outlined for the work this year was in detail as follows, a hydrochloric acid solution 

 of the ash being used: 



SEPARATION OF FERRIC AND ALUMINIC OXIDS IN ASH ANALYSIS. 



Use a solution corresponding to 0.2 gram of ash. After removing the phosphoric 

 acid the filtrate from the precipitate of ammonium phosphomolybdate, consisting of 

 a nitric acid solution of molybdic acid, ferric oxid, alumina, lime, and magnesia, is 

 placed in a beaker and cautiously neutralized with ammonia, care being taken that 

 the temperature does not rise above 40 C. and that the alkali is added only in slight 

 excess; allow to stand in a warm place until the precipitate completely settles, filter 

 the clear supernatant fluid, wash the precipitate with hot water by decantation, 

 then transfer it to the filter, and finish the washing. Next, redissolve the precipitate 

 through the filter in weak, hot nitric acid (1 to 5), reprecipitate with ammonia, filter,- 

 and wash in the same careful manner. The precipitate is dried, ignited, and weighed 

 as ferric oxid and alumina. 



METHOD (b). The weighed precipitate of ferric oxid and alumina is dissolved, 

 on the hot water bath, in a covered flask by the addition of about 20 cc of dilute sul- 

 phuric acid (1 part sulphuric acid to 4 parts water). The iron is reduced to the ferrous 

 state by adding iron-free metallic zinc (about 5 decigrams at each addition) until 

 the solution is completely decolorized and the iron is all reduced; cool by immersing 

 in cold water, dilute with cold distilled water which has been recently boiled, pour 

 off and wash into beaker, leaving behind any residue of zinc. Titrate with standard 

 permanganate solution. 



METHOD (c). An aliquot part of the original solution A, corresponding to 0.2 gram 

 of ash, is evaporated on hot water bath with the addition of 10 cc of sulphuric acid 

 until all hydrochloric acid is expelled; dilute with water, reduce with zinc, and 

 estimate iron by standard solution of potassium permanganate. The per cent of 

 ferric oxid obtained is deducted from the per cent of ferric oxid and alumina, cor- 

 rections being made for filter ash, to obtain the per cent of alumina. 



