NOTES. 295 



ascertaining of whether the establisliineut of certain standards of nitroson 

 activity for raw materials and mixed fertilizers furnishing organic nitrogen is 

 warranted. The materials studied were tartar pomace, dried blood, nitrogenous 

 manures containing about G, 8, and per cent of nitrogen, beet-root manure, 

 and a mixture consisting of beet-root manure and nitrogenous manure 3:1. 



The previous experiences that both the Jones and Street methods are satis- 

 factory for differentiating between good and poor organic nitrogenous material 

 were confirmed by this year's work, with, one exception. The Jones method 

 gave results more in accordance with pot tests than the Street metliod and is 

 somewhat shorter, but the work showed that in the hands of inexperienced 

 persons more uniform figures are obtained by the Street method. Both methods 

 are to be further studied with tlie view of increasing tlie accuracy of the water- 

 msoluble nitrogen determination, and in the case of the Jones method to over- 

 come the difficulties experienced by most analysts in the distillation with alka- 

 line permanganate. 



Collaborative results with the Kjeldahl-Gunning-Arnold method in its present 

 state on the whole were very satisfactory. When copper sulphate was used 

 in lieu of oxid of mercuiy the time of digestion was somewhat prolonged, and 

 the method, although adopted as official, is to be further studied. Nitrogen 

 determinations by the Gunning copper method and the Kjeldahl-Gunning- 

 Arnold method wei'e made by A. J. Patten on a large variety of animal and 

 vegetable materials. The results reported by the cooperating analysts with 

 the zinc-ferrous sulphate-soda method for nitrates indicated that more work is 

 necessary before it can be recommended for adoption as official. 



The associate referee on the availability of potash, E. E. Vanatta, gave a 

 report of progress on a series of pot culture experiments in conjunction with 

 the department of soils of the Missouri Station, for tlie puri^ose of studying the 

 effect of different soil treatments on the availability of potash in ground 

 feldspathic rock. The availability was measured by plant (corn) growth sup- 

 plemented by chemical determinations. 



Work on the determination of potash, reported by T. D. Jarrell, associate 

 referee, included cooperative tests on (1) the use of denatured alcohol for 

 washing potassium platinic chlorid; (2) the necessity for the use of hydro- 

 chloric acid in the water extract; and (3) the perchlorate method. The sam- 

 ples tested were commercial muriate of potash, kainit, and a mixture of kainit 

 and acid phosphate. The results obtained collaboratively with the perchlorate 

 method showed quite a variation, and with mixed fertilizers it consumes too 

 much time, but it was concluded that in tlie hands of analysts familiar with 

 its limitations, and with some modifications, especially with regard to the 

 method of washing the potassium perchlorate, it might give reasonably uniform 

 and dependable results. Ethyl alcohol denatured with methyl alcohol, or with 

 benzin and methyl alcohol, can apparently be safely used as a wash for 

 potassium platinic chlorid. but pyridin can not be used as a denaturant. 



In the collaborative work comparing the official method with modifications 

 in which the addition of hydrochloric acid was omitted, certain differences were 

 noted, but all results were well within the limits of experimental error. The 

 association next year is to study why hydrochloric acid is added to the potash 

 extract, the perchlorate method with regard to washing the perchlorate pre- 

 cipitate, and the use of denatured alcohol. 



J. W. Ames, referee on soils, in discussing means for estimating organic 

 carbon in soils containing carbonates pointed out that the official method for 

 carbon dioxid in soils was indefinite. He reported a study of methods for 

 determining inorganic carbonic acid and organic carbon in soils, and some data 

 obtained with other methods. A further test of methods for the determination 



