716 EXPERIMENT STATION RECORD. 



ity of tlie high moor peat types was low and that of the low moor types gen- 

 erally high. The lime-magnesia ratio in all the types varied between wide 

 limits and approached unity only in peat very poor in lime. Easily ^luble 

 alkalis were present only in very small amounts in any of the types while 

 the iron oxid content was generally high. In peats with a high ash content 

 inorganic sulphur compounds were found while organic sulphur was present 

 in peats having a low ash content. Phosphoric acid was seldom found in note- 

 worthy amounts. 



The peat-forming plants investigated were rich in potash and phosi")horic 

 acid but had a very variable lime content. Extraction by solvents was best 

 effected when using the peat in fine dust form intermixed with clean sand. 

 Alcohol generally produced the largest amounts of extract and petroleum 

 ether the least, and a so-called pollen muck peat yielded the greatest extract 

 of all the peat types. The bleached moss peat extract increased with the age 

 and decomposition of the peat, being greatest with petroleum ether and least 

 with alcohol as the solvent. 



The heat of combustion of the peat types generally decreased with Increased 

 ash content and varied according to botanical composition, condition of decom- 

 position, and the content of alcohol soluble matter. 



The products of distillation from the different peat types and muck formations 

 depended upon the lime and nitrogen content, as all peats poor in lime and 

 nitrogen gave acid distillates while those rich in lime and nitrogen gave alka- 

 line distillates. 



The nature and amount of the fluctuation in nitrate contents of arable 

 soils, K J. Russell (Jour. Agr. Sci. [England], 6 (1914), No. 1, pp. 18-57, 

 figs. 2; ahs. in Jour. Soc. Chem. Indus., 33 (1914), No. 4, p. 210).— In extended 

 studies of the nitrate content of arable soils, it was found that in sand, loam, 

 and clay soils this fluctuated regularly, but rarely exceeded 6, 23, and 14 parts 

 per million respectively in the soils except when they were heavily manured, 

 when it sometimes rose to 37 parts. In most of the soils tested the accumula- 

 tion of nitrate took place most rapidly in late spring or early summer, after 

 which there was usually little if any gain and frequently a loss, except in the 

 hot, dry summer of 1911 when the accumulation continued in some of the soils 

 until September. Losses of nitrate occurred during the winter and were more 

 marked during a wet than during a dry winter. 



The fluctuations in nitrate content were more marked on loams than on 

 clays or sands. Clays lost less of their nitrates in winter but accumulated 

 smaller amounts in June and July. Sands lost much of their nitrates in winter 

 and did not accumulate very large amounts in summer. " It appears that the 

 main loss in winter is due to leaching and not to denitriflcation." A compari- 

 son of nitrate contents of cropped and fallow land showed that during late sum- 

 mer and early autumn the fallow land was the richer even after adding the 

 nitrate taken up by the crop. No evidence was found that nitrate was pro- 

 duced in the soil during the time of active crop growth, although nitrate accu- 

 mulation was taking place on adjacent fallow land. " The rapid rise in nitrate 

 content in spring does not usually set in immediately the warm weather begins; 

 there is a longer or shorter lag. There are indications of greater bacterial 

 activity in early summer than later on." It is concluded " that the factors 

 which determine the accumulation of nitrates in the soil also play a 'great part 

 in determining the amount of crop production. Thus heavy winter rainfall, 

 which washes out nitrates, tends to reduce crop growth ; on the other hand hot 

 dry summers succeeded by dry winters are favorable to nitrate accumulation 

 and therefore to crop growth." 



