792 EXPERIMENT STATION RECORD. [Vol.43 



and from 4.G to 5.8 in the Witte peptone-phosphate-glucose medium. The final 

 hydrogen-ion concentration of the cloac^e-serogenes type could not be accu- 

 rately determined on account of the simultaneous acid and alkali production. 

 The pH value obtained under similar conditions ranged from 6 to 7.4 in the 

 Witte peptone medium and from 6 to 6.8 in the synthetic medium. 



" The respective hydrogen-ion concentrations of the colon and serogenes 

 types of bacteria may be adequately determined for practical purposes by 

 methyl red as an indicator, provided the neutral tint reactions are compared 

 with the reactions obtained by brom cresol purple or some other sharp indicator 

 as a check." 



The Voges and Pro.skauer method of distinguishing between B. coli and B. 

 (erogenes jiroved even more satisfactory than the methyl red test, in that it 

 was simple in operation and when correctly carried out thoroughly constant 

 in its results. When used with precaution the uric-acid test also was of funda- 

 mental importance in differentiating fecal coli from the soil serogenes type of 

 bacteria. No definite correlation could be established by means of the indol test. 

 Neither did motility study prove to be of practical value. Adonitol fermenta- 

 tion did not prove itself to be a satisfactory method of differentiating fecal 

 from nonfeca! strains of B. irrogenes. 



A list of 80 references to literature bearing on the subject is appended. 



Home laundering, L. R. Balderston (V. S. Dept. Ayr., Farmers' Bui. 1099 

 (1920), pp. 32, figs. 12). — Methods and equipment for home laundering are de- 

 scribed and illustrated, the purpose being to introduce convenience, economy, 

 and saving of labor in the laundering process. 



KTJRAL ECONOMICS. 



Farm business analysis studies, H. M. Dixon {Jour. Farm Econ., 2 (1920), 

 No. 2, pp. 87-100, fig. 1). — Data accumulated in the Office of Farm Management 

 of the U. S. Department of Agriculture by investigations of the same farms over 

 a period of successive years and by repetition studies in the same area after a 

 lapse of a period of years are compared and summarized in this paper, the aim 

 iieing to illustrate the fund of material made available by such investigations. 



Table 1 gives a summary of the results of four studies in Ohio and Indiana 

 over seven years, Wisconsin over five years, and New Jersey over three succes- 

 sive years. The farnt area, crop area, value of real e.state per acre, productive 

 animal units, number of work stock, months of labor, and investment per farm 

 are shown for each of the four areas. The next table shows the percentage in- 

 crease in receipts and expenses in the Ohio and Indiana areas for the years 

 affected by increased prices and costs. Table 3 is in the form found satisfactory 

 for showing the summary of the farm business, this one relating to that of a 

 period of seven years on 100 farms in Clinton County, Ind. Table 4 summarizes 

 results from a study of 500 white owner farms in Sumter County, Ga., made 

 first in 1913 and repeated in 1918. The following table deals with farm loans 

 and interest rates on these farms for the two periods, and the next with the 

 cash required per farm for operating expenses and its sources, whether bor- 

 rowed or furnished by the operator. Table 7 makes comparison of the use of 

 man labor, mule labor, and machinery in the same area. The last is a chart, 

 showing the number of farms producing cotton at various costs for the two 

 years and variation in the cost. 



Cost and price tendencies on the farm, R. M. Green {MissovtH Sta. Circ. 

 97 {1920), pp. 8, figs. 7). — Table 1 in this circular shows the cost and price 

 indexes on corn, wheat, pork, and beef from 1915 to July, 1920, inclusive, based 

 on the average for 1910-1914, inclusive, and Table 2 the average labor inconres 



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