12 EXPERIMENT STATION RECORD. 



In the solutions in variable amounts, the average being 9.98 per cent of the 

 soluble nitrogen. The percentages of nonbasic nitrogen, determined by differ- 

 ence, proved to be quite concordant in most of the soils, amounting on the 

 average to 64.57 per cent of the soluble nitrogen." 



The amids constitute a much higher percentage of the nitrogen of soils than 

 are said to occur in vegetable proteins. On the other hand, the percentage of 

 basic nitrogen was far less than exists in the majority of vegetable proteins. 



The aquatic (anaerobic) soils showed a higher percentage of total nitrogen 

 soluble in hydrochloric acid. On an average 70.69 per cent of total nitrogen 

 was obtained from the aerated soils and 87.93 per cent from unaerated soils. 

 This indicates that a putrefactive process predominates in submerged soils, 

 as previously indicated (E. S. R., 30, p. 420), which leaves the nitrogenous 

 substances more easily soluble in hydrochloric acid. " The amount of nitrogen 

 soluble in 1 per cent hydi'ochloric acid was about twice as large as that of ammo- 

 nia originally occurring in the soils. The solubility in 3 per cent sodium hydrate 

 varied from 49.56 per cent to 76.62 per cent of the total nitrogen. Of the nitro- 

 gen thus dissolved, 57.85 per cent was precipitated by dilute hydrochloric acid, 

 of which 11.93 per cent (expressed in percentage of the humus nitrogen) 

 remained insoluble after boiling in strong hydi-ochloric acid for 10 hours. 

 Amids comprised 28.77 i3er cent of the humus nitrogen, of which about one- 

 half existed as amid in the original humus solutions, and which remained In 

 solution upon acidifying with hydrochloric acid. The remaining half was 

 split off when the humus, precpitated by hydrochloric acid, was subjected to 

 acid hydrolysis. The basic nitrogen ranged from 4.39 per cent to 44.83 per 

 cent of the humus nitrogen, increasing as the total nitrogen of the humus 

 decreased. Nonbasic nitrogen was found to constitute 53.38 per cent of the 

 humus nitrogen, of which 25.05 per cent existed as such in the original humus 

 solutions. 



"The amounts of amid and basic nitrogen in humus expressed as percentages 

 of the humus nitrogen were found to be higher than the amounts obtained by 

 subjecting the original soil to hydrolysis. In view of the large amounts of 

 amid occurring in humus solutions, it was found better to use sodium hydrate 

 as the solvent for extracting humus that is to be used for total humus nitrogen 

 determinations. The humus of Hawaiian soils contains a small percentage of 

 nitrogen (5.88 per cent as an average of 22 samples), in which respect the 

 humus of these soils closely resembles that found in humid soils in the States." 



See also previous notes by others (E. S. R., 25, pp. 622, 623; 26, pp. 320, 

 615, 616; 28, p. 813). 



Some organic constituents of the culture solution and the mycelium of 

 molds from soil, M. X. Sullivan (Ahs. in Science, n. ser., 38 {1913), No. 984, 

 p. 678). — ^An examination was made of the dried mycelium of mixed mold cul- 

 tures from soil and of Penicillium glaiicnm grown on Raulin's solution and of 

 the filtered solution after mold growth for organic constituents. 



" In the mixed molds was faund a large number of organic substances, 

 many of which were subsequently found in P. glaucwn. In the alcoholic soda 

 extract of P. glaucum were found oleic and palmitic acids, a fatty acid melting 

 at 54° C, a fatty acid which appears to be elaidic acid, hypoxanthin, guanin 

 and adenin, histidin, thymin, and chlorin. In the direct alcohol extract was 

 found mannit, cholesterol bodies, hypoxanthin, and cerebrosids. From mold 

 grown on Raulin's solution plus peptone a small amount of guanidin was found. 

 In the culture solution after a number of weelis' growth were found fatty 

 acids, purin bases, a small quantity of a histidin-lilfe body, pentose sugar, 

 unidentified aldehydes, etc. Many of these compounds have been found in soil 



