SOILS FERTILIZERS. 715 



The average proportion of nitrogen in the humus of the first foot of tlie soils 

 was found to be 5.02 per cent ; that of each of the upper 3 ft., 5.6 per cent, and 

 somewhat less for the entire 12 ft. It varied from 1 to 20 i>er cent in individual 

 soil layers. 



The organic nitrogen in the soil derived from the humus and dei>endent upon 

 the amount of the latter varied from almost nothing in the lower depths of 

 the soil to as much as 0.13 i>er cent in the upper 3 ft. in upland soils. The 

 average for the first foot of the soil was 0.07 per cent; for each of the upper 

 3 ft. it was 0.05 per cent. 



Wide distribution of humus and nitrogen in California soils tends to extend 

 the feeding area of roots of plants and thus increas*» their jx)wer of resistance 

 to drought. 



The humus of acid and alkaline peats, J. A. IIanley (Jour. Agr. Set. [Eng- 

 land], 6 {1914), No. 1, pp. 63-76; ahs. in Jour. 8oc. Chcm. Induf<., SS (1014), 

 No. 4, P' 210).— Experiments with a number of acid, neutral, and alkaline 

 peats to determine a safe method for distinguishing chemically between the 

 different classes as regards acidity and alkalinity are reported. 



Preliminary te.sts of 35 peats led to the conclusions (1) that in every soil 

 containing an appreciable quantity of organic matter, part of the humus is 

 soluble in ammonia without previous acid treatment, (2) that soils containing 

 no calcium carbonate give an acid reaction to litmus and vice versa. More de- 

 tailed studies of the humus of five different typical peats gave the following 

 results: Ammonia apparently dissolved out substances of very nearly the same 

 nitrogen content w^hother or not the peat was previously treated witb acid, and 

 the composition of the humus as regards nitrogen varied only slightly in dif- 

 ferent peats. Caustic soda gave lower and more significant results than 

 ammonia in all cases, indicating that the soda dissolves " either different com- 

 pounds or different kinds of the same compounds." An estimation of the 

 nitrogen formed by hydrolysis of proteins and similar compounds in the five 

 peats showed that only the alkaline peats yielded ammonia and this in small 

 amounts. 



Tests of the sucrose-inverting powers of the peats showed that this power 

 varied considerably with the different peats and in every case the inversion was 

 greater after acid treatment than before. Further tests of the sucrose-invert- 

 ing powers of soils led to the conclusion that " the acidity of a soil does not 

 depend on the actual proportion of the acid in the soil . . . [but] on the state 

 of the organic matter in the soil and the proportion of it which is in an acid 

 state. ... In estimating acidities, then, it is necessary to know not only the 

 proportion of humus in an acid state to the total soil but the proportion of 

 •humus' as ' humic acid' to 'humus' as ' humates,' and this involves a deter- 

 mination of sugar inverted after treatment with dilute acid." 



It is concluded in general that it is never safe to .iudge the acidity of a soil 

 from the percentage of it directly soluble in alkalis. It api)ears as though some 

 less general property of acids than solubility in alkalis must be used, in which 

 neutral compounds can not take part, such as inversion of sucrose. 



Contribution to the knowledge of typical kinds of peat, II. Minssen 

 (Landw. Jahrb., 44 (1913), No. 1-2, pp. 269-330; ahx. in Zcnthl. Agr. Chcm., 

 42 (1913), No. 12, pp. 796-799).— Studies of numerous samples of peat typical of 

 the high, intermetliate, and low moors of Germany as regards their physical 

 and chemical composition, plant and animal origin, heat of combustion, and the 

 determination of quantities of extract using alcohol, ether, and petroleum ether 

 as solvents are reported. 



Ash analyses showed a low mineral content of the forest peats and a relatively 

 high mineral content of the muck formations. The lime content of the major- 



