1918] AGEICULTURAL CHEMISTRY AGROTECHNY. Ill 



The relative influence of microorganisms and plant enzyms on corn silage 

 fermentation, A. R. Lamb (lotva Sta. Research Bid. JfO (1917), pp. S1S-S32, figs. 

 IS). — This material has been noted from another source (E. S. R., 36, p. 802). 



Note on orange pip oil, Dorothy G. Hewer (Analyst, 42 (1917), No. ^97, pp. 

 271-273). — The author has examined a sample of orange seeds obtained as a 

 by-product in the production of marmalade. The seeds consisted, in parts by 

 weight, of kernel 69 and shell 31 per cent, and yielded on extraction with 

 petroleum ether 37.5 per cent of a golden yellow oil equivalent to 54.95 per 

 cent of the weight of the kernels. The oil was almost odorless and when 

 freshly extracted had only a slightly bitter flavor. The bitterness, however, 

 increased considerably and rapidly on keeping. 



The following constants were obtained : Saponification value, 193.7 ; unsaponi- 

 fiable matter, 0.14 per cent ; iodin value, 100.3 ; refraction at 40° C, 57.5 ; free 

 fatty acids, as oleic, 0.3 per cent ; specific gravity at 15°, 0.9208; titer test, 34° ; 

 neutralization value, 200.1. 



It is indicated that s:nce the oil is easily saponified it should prove suitable 

 for soap and glycerol manufacture. » 



Some factors influencing tlie quantitative determination of nitric nitrogen 

 in the soil, J. E. Greaves and C. T. Hirst (Soil ScL, 4 (1917), No. S, pp. 179- 

 205, figs. 2). — In the course of investigations the authors, at the Utah Experi- 

 ment Station, found that clear soil extracts could be obtained by adding 2 gm. 

 of lime, ferric sulphate, ferric alum, sodium alum, or potassium alum to the 

 soil-water mixture, by filtering through the Chamberland-Pasteur filter, or by 

 centrifugal!zation. 



The use of alum, the Pasteur filter, or centrifugalization yielded a clear 

 .solution with a minimum loss of nitric nitrogen. The use of calcium oxid 

 yielded a clear supernatant solution, but the quantity of nitric nitrogen ob- 

 tained from such a solution was low. This is conceded not to be entirely due 

 to the mechanical removal of the nitric nitrogen with the precipitated colloid, 

 for similar results were obtained when calcium oxid was added to a clear 

 sodium nitrate .solution. The ratio of soil to water was found not to have 

 any great influence on the quantity of nitric nitrogen obtained, since the same 

 amount was obtained from the soil when the ratio varied from as low as 1 : 5 

 to as high as 1 : 25. No increase in nitrogen was obtained by shaking more 

 than five minutes, provided the soil was well pulverized and thoroughly 

 agitated. 



Chlorids, sulphates, or carbonates of .sodium, potassium, calcium, magnesium, 

 manganese, and iron were indicated as not interfering with the Ulsch reduc- 

 tion method (E. S. R., 3, p. 654). The presence of urea or glycocoll, however, 

 yielded high results unless the solution was evaporated to dryness before 

 reduction. No loss of nitric nitrogen was observed when such a solutioa was 

 evaporated to dryness. " When dried blood is mixed with a nitrate less than 

 100 per cent of the nitric nitrogen is recovered by this method. There can be 

 but little doubt that this is due to the reacting of nitrate with the proteins of 

 the blood. If the resulting compound is insoluble it will settle from the 

 supernatant liquid and thus be lost, while, if soluble, subsequent reduction will 

 fail to liberate the nitric nitrogen ; hence we would find the same error entering 

 with any of the other methods." 



The aluminum x'eduction method, as modified by Burgess (E. S. R., 31, p. 

 206), permits of an appreciable loss of nitric nitrogen. This is obviated, how- 

 ever, by the use of the Iron reduction method, which is outlined as follows : 



One hundred gm. of finely ground soil, together with 500 cc. of distilled water, 

 are placed in quart Mason jars and agitated for five minutes, preferably In a 

 shaker. The solution Is then clarified by either the addition of 2 gm. of alum 



