EXPERIMENT STATION REPORTS. 173 



consumption of commercial fertilizers is still on the increase and will 

 keep on increasing as the farmers of the state gain a better and clearer 

 understanding of how and when to use them. 



The following bulletins have been published during the year: 



No. 263 — "Fertilizer Analyses" — Andrew J. Patten, O. B. Winter and 

 C. G. Clippert. 



Technical Bulletin, No. 6 — ''Lime-Sulfur Spray" — Jas. E. Harris. 



Technical Bulletin, No. 7 — "Organic Nitrogenous Compounds in 

 Peat Soils" II. — Chas. S. Robinson. 



Circular No. 10 — ''Manufacture and Storage of Lime-Sulfur Spray" 

 — Andrew J. Patten. 



I regret exceedingly to record the resignation of Mr. O. B. Winter, 

 who has accepted a more remunerative position with the New York 

 State Agricultural Experiment Station, Geneva, N. Y. Mr. Winter has 

 been connected with the division since February, 1910, and his zealous 

 performance of the duties assigned to him have made him a very valuable 

 man and his going will be a distinct loss to the institution. 



Mr. Clarence Clippert severs his connection with the division with the 

 close of the fiscal year and Arao Itano, a graduate of the college, has been 

 engaged for one year. 



In conclusion I wish to express my appreciation to my associates 

 for their untiring interest in the welfare of the division and for the 

 pleasant relations that have prevailed. 



ANDREW J. PATTEN, 



Chemist. 



East Lansing, Mich., June 80, 1911. 



Note. — The following papers upon "Neutral Ammonium Citrate Solu- 

 tions" and the use of Busch's "Nitron" for the Determination of Nitrate 

 Nitrogen in Soils and Fertilizers are here published as of interest in 

 connection with the report of the chemist. (Editor.) 



NEUTRAL AMMONIUM CITRATE SOLUTIONS, i 



■ BY A. J. PATTEN AND C. S. ROBINSON. 



Since the proposal of the neutral ammonium citrate method for the 

 determination of available phosphoric acid much trouble has been ex- 

 perienced in preparing a strictly neutral solution of the reagent. The 

 weakness of both the acid and the base renders, the end point quite 

 indistinct with ordinary indicators and much time and patience are re- 

 quired on the part of the operator to obtain the desired results. Sev- 

 eral complicated modifications of the simple titration method have been 

 proposed but each has objections which prohibit its common acceptation 

 by practical chemists. The importance which the method has assumed 



iQwing to trouble with apparatus and the interference of other worR progress on these 

 experiments was retarded and before their completion an excellent article by Hall and Bell 

 appeared (Journ. Amer. Chem. Soc. 33, 711,) in which it was shown to be possible to use 

 the method outlined. A second article by Hall has since been published (Jour. Ind. 

 and Eng. Chem. 3, 559,) pointing out the practicability of the method for common use. 

 The results given add but little to the material in the above articles and their 

 publication was withheld for some time. It has since been deemed wise to publish them 

 however as corroborating the work of the above authors. They also show through what 

 a wide range the so-called "neutral" ammonium citrate solutions may vary as prepared 

 by the official method. 



