122 



SCIENCE 



[N. S. Vol. SLVI. No. 1179 



closely agreeing results ean be obtained by using 

 the proper method. 



A metliod for estimating starch: W. S. Long. 

 A method is proposed for the estimation of small 

 quantities of starch in food products, and is based 

 upon the precipitation of starch as the iodide. 

 The method yields results of a fair degree of ac- 

 curacy with weak starch solutions, and has been 

 found applicable to the determination of small 

 quantities of starch in jellies and jams. 



The use of alfalfa flour in human nutrition: 

 Elizabeth C. Sprague. Alfalfa flour is the finely 

 powdered leaves of the dried plant. It contains 

 practically no starch and is not a flour withiu the 

 meaning of the term as applied to cereal flours. 

 It can, however, be blended with cereal flours. In 

 its unpurified state it is rank in flavor and imparts 

 to the mixture an undesirable dark green color. A 

 method is described by which the color is removed 

 and the flavor materially modified. The propor- 

 tions in which the purified product can be added 

 to other flours are given. The blending of alfalfa 

 and wheat flours increases considerably the nitro- 

 gen and the mineral contents of the preparations 

 in which it is used. Samples were shown of breads 

 in which the blended flour was used. 



The effect of prolonged ■production of alfalfa on 

 the nitrogen content of the soil: C. O. Swanson. 

 Kansas has a number of fields in which alfalfa has 

 been growing continuously for twenty to thirty 

 or more years. While most of the fields are found 

 in the middle and western part of the state, a few 

 old flelds are also found in the eastern part. 

 Near most of these fields is found soil of the same 

 type which has been continuously cropped to grain, 

 usually wheat and corn, for thirty to forty years 

 or more, and soil in native sod, used either as pas- 

 ture or hay land. By sampling such fields close to- 

 gether and analyzing the soil, data are obtained 

 that show the rate at which nitrogen disappears 

 from the soil continuously cropped to grains; the 

 nitrogen content of the soil which has never been 

 broken; and by comparison it is possible to calcu- 

 late the amount of increase or decrease in nitrogen 

 in the soU on which alfalfa has been growing for 

 a long time. 



Variations in the ether extract of silage: L. D. 

 Haigh. The analysis of a sample of corn silage 

 some months after the first analysis shows that 

 the composition of the dry matter has changed. 

 There has been a loss in the amount of ether sol- 

 uble material and crude fiber, especially the 

 former constituent. Also the percentage of mois- 

 ture and ether extract of silage at any one time 



will vary according to the method of drying. The 

 acidity of silage seems to be largely the cause of 

 change of composition on standing and the vary- 

 ing results on drying. The conclusions are that 

 the corn sUage should be analyzed promptly to ob- 

 tain the composition of the silage as used. Also 

 variations due to drying may be avoided by the use 

 of the vacuum method throughout. 



The occurrence and action of molds in soils: P. 

 E. Beown and W. V. Halversen. Attention is 

 directed to the importance from the fertility 

 standpoint of the occurrence and action of molds 

 in soils. These organisms have been found to occur 

 in practically all soils, not only in a spore state, but 

 also in an active form. In general, the numbers 

 present have amounted to about one tenth of the 

 total number of bacteria present. Their action is 

 varied, but they have been definitely shown to 

 bring about the destruction of cellulose and the 

 breaking down of protein, producing in the latter 

 process much ammonia. Inorganic compoimds in 

 the soil are also affected by mold growth and 

 available phosphorus and sulfur are both produced 

 in considerable amounts by these organisms. 



Sulfofication in manures and its influence on the 

 production of available phosphorus from floats: 

 P. E. Brown and H. W. Warner. Mixtures of 

 flowers of sulfur with compost, horse manure, or 

 cow manure allowed to ferment for varying lengths 

 of time showed a rapid oxidation of the sulfur 

 with the production of sulfuric acid. These 

 manures evidently possess a vigorous siilfofying 

 flora. Eock phosphate when composted with horse 

 manure and cow manure is reduced in availability, 

 evidently due to an increased development of 

 phosphorus-assimilating organisms. The reverse is 

 true when the floats are mixed with compost. 

 When sulfur and floats together are composted 

 with the various manures there is an enormous in- 

 crease in the production of available phosphorus, 

 which continues up to flfteen weeks. A practical 

 method for producing acid phosphate on the farm 

 is suggested by composting sulfur, floats and 

 manure in the proper proportions. 



Identification of added colors in dutter and oleo- 

 margarine: H. A. Ltibs. The various tests for the 

 detection of added color in butter and oleomarga- 

 rine are discussed and their limitations are de- 

 scribed. Suggestions are made for the improve- 

 ment of the various tests. A method is described 

 for the isolation of o-toluene-azo-ff-naphthylamine 

 and benzene azo-/3-naphthylamine from butter and 

 oleomargarine and a method for their identification 

 is given. 



