July 15, 1921] 



SCIENGE 



57 



DIVISION OF AGRICULTDKAL AND FOOD CHEMISTKT 



C. E. Coates, chairman, 

 T. J. Bryan, secretary. 



Suggestions for more rapid and exact methods 

 of analyses for the cheese factory: S. K. Eobinson. 



Some problems of the pure food manufacturer : 

 H. A. NoYES. The preserver of fruit and fruit 

 products has two important problems to solve: 

 (1) The obtaining of a high quality and uniform 

 fruit supply each year, and (2) the processing of 

 fruit in such a way that its natural properties are 

 retained. The pure food manufacturer's inability 

 to accomplish these two things up to the present 

 has allowed the artificial flavor and color manu- 

 facturer to develop his products and befuddle the 

 taste of the average consumer. The plans and 

 organization of one large concern, to study the 

 production of quality fruits and to apply research 

 methods to its business, were given. 



Variations in the Concord grape during ripen- 

 ing : H. A. NoYES, H. T. King, J. H. Mart- 

 SOLF. Variations in the Concord grape during 

 ripening that are of interest to the juice and jam 

 manufacturer were investigated. Eesults show a 

 gradual increase in sugar content, a decrease in 

 total acids and irregularities in tannin and color- 

 ing matter. Weather conditions were an impor- 

 tant factor affecting sugar content, warm days 

 and cool nights seeming to be the optimum con- 

 dition for developing sugar. 



The absorption of copper from the soil by. 

 potato plants: F. C. Cook. Insoluble copper 

 compounds present in a Bordeaux spray contain- 

 ing an excess of lime and present in Pickering 

 spray containing no excess of lime, also a solu- 

 tion of sulfate of copper, were added to the soil 

 near the roots of potato plants in equal strengths 

 and amounts at various intervals during the grow- 

 ing season. Samples of vines, tubers and soil 

 were taken for analyses at frequent intervals. The 

 leaves of the plants grown in the soil receiving the 

 insoluble copper, i.e., the sprays, held the largest 

 part of the copper, the roots but little and the 

 stems an intermediate amount. The tubers con- 

 tained but traces of copper. Where the soil 

 ■was treated with the copper sulfate solution the 

 roots were injured and the normal metabolism of 

 the vines interfered with. The tubers from these 

 vines were small and the vines stunted. In these 

 plants the roots held more copper than the leaves. 

 The soluble copper sulfate added directly to the 

 soil caused injury to the plants while the insoluble 



copper compounds of the sprays did not. The 

 extra lime of the Bordeaux spray did not reduce 

 the amount of copper absorbed by the plants com- 

 pared with the results on the Pickering plants. 

 Where the sprays and copper sulfate solution were 

 added to the soil directly practically the same 

 amounts of copper were recovered from the soil 

 samples. Samples of soil from sprayed potato 

 fields showed but minute amounts of copper._^ 



PicTcermg Bordeaux sprays: F. C. Cook. 



Analysis of the Jerusalem artichoTce: A. T. 

 Shohl. The Jerusalem artichoke, Selianthus tu- 

 berosus, gives the analysis: 



Water Nx6.25 Fat Carb. Fiber Ash 

 Per cent... 79.0 3.1 .2 16.5 .8 1.1 



The wastage by peeling is 31 per cent., the hy- 

 drogen ion concentration (colorimetric) pH 5.0. 

 The carbohydrate is inulin, as determined by po- 

 lariscope and quantitated after inversion by Bene- 

 dict's solution. Experiments show it is utOized, 

 and not excreted by diabetics. The nitrogen is 

 largely extracted with boiling water. This non- 

 protein fraction represents 71.5 per cent, of total 

 nitrogen. Of the water soluble non-protein nitro- 

 gen 26 per cent, is free amino acid nitrogen and 

 12 per cent, ammonia nitrogen. 



Measuring soil toxicity, acidity and basicity: 

 E. H. Caek. 



What puts the "pop" in pop corn? E. H. 

 Carr. (Lantern.) 



The rate of oxidation of lime-sulfur: C. A. 

 Peters and A. L. Prince. The rate of oxidation 

 of Ume-sulfur is largely independent of the con- 

 centration and also of the temperature up to about 

 80°, when the rate is increased in all but the 

 very dilute solutions. 



A color test for "remade" milk: Oscar L. 



EVENSON. 



Effect of aging on lecithin-phosphoric acid de- 

 termination of egg noodles: E. C. Hummell. The 

 resiilts of these experiments indicate that aging 

 does have considerable effect on the lecithin-phos- 

 phoric acid determination in egg noodles. By the 

 end of six months this value had decreased to less 

 than two thirds of the original value and in eigh- 

 teen months had decreased to one half or less 

 than one half of the original amount. Inasmuch 

 as considerable time may elapse from the time 

 at which egg noodles are manufactured until they 

 reach the consumer, it would seem to be quite in 



