SOILS FERTILIZERS. 423 



cumulation of nitrates in the soil to a greater extent than sodium nitrate. 

 There was little leaching of nitrates during rainy periods and this was not 

 noticeable in any case below 25 to 50 cm. 



The observations in the spring of 1912 were made on the same plats used in 

 the earlier experiments which had in the meantime been seeded to winter wheat. 

 In general, considerably less nitrate was found than during the preceding sum- 

 mer. The loss of nitrates by leaching was less pronounced on plats fertilized 

 with nitrogenous materials and which, therefore, had a heavier growth of wheat. 



The prevention of loss from manure heaps in winter and early spring', 

 E. J. Russell and E. H. Richards {Jour. Bd. Agr. [London^, 21 (1914), No. 9, 

 pp. S00-S07, fig. 1; als. in Jour. Soc. Chein. Indus., 34 {1915), No. 2, p. 93).— 

 Observations were made on the losses of nitrogen and phosphoric acid in heaps 

 of manure stored in the open and under shelter. 



Of two heaps stored in the open, one lest 25 per cent of its nitrogen from 

 January to April and the other 33 per cent of its nitrogen fi'om November to 

 May. The loss of nitrogen fell most heavily on the easily available portion, 

 that is, the ammonia and the amids. There was a loss of about 8 per cent of 

 the phosphoric acid. In the case of the manure stored under cover, the loss of 

 nitrogen was 6.9 in one case and 7.9 ;n the other, and there was no loss of 

 phosphoric acid. 



The experiments indicated that rain was the most potent source of loss. That 

 the loss is not due to leaching was shown by experiments in which the manure 

 heap was artificially watered but not to the extent of causing increased leach- 

 ing. The artificial watering caused a large loss of nitrogen as compared with 

 the unsprinkled manure heap. 



The conclusion is reached that the loss of nitrogen fi-om an exposed manure 

 heap is not due to volatilization of amaionia to the extent that it is generally 

 supposed to be nor entirely to leaching, but that a considerable proportion of 

 the loss is due to the fact that nitrates are formed on the surface of the 

 manure; these nitrates are washed down by the rainfall into the interior of the 

 heap and are rapidly decomposed with the escape of free nitrogen. Observa- 

 tions are also reported which indicate that considerable loss in nitrogen results 

 from any turning over or moving of the manure heap, but the cause of this was 

 not established. 



The results in general indicate that losses in manure can be practically pre- 

 vented by compacting and storing under cover. They show that the pumping 

 of liquid manure on to a manure heap does not reduce the loss. 



Purification of sewag'e by aeration in the presence of activated sludge, E. 

 Bartow and F. W. Mohlman {Jour. Indus, and Engin. Chem., 7 {1915), No. 4, 

 pp. 318-320, figs. 3). — This is an account of experiments carried on in the 

 laboratory of the Illinois State Water Survey at the University of Illinois test- 

 ing a modification of Fowler's aeration method for the treatment of sewage. 



As a result of the treatment there was obtained a sludge containing large 

 numbers of microscopic animals, predominant among which was an annelid 

 worm {Aeolosoma hemprichi), which appear to play an important part in the 

 reduction of the sludge. Analyses of the sludge showed 95.54 per cent of water ; 

 the dry matter contained 6.3 per cent of nitrogen, 1.44 of phosphorus, and 

 4 of fat. In pot tests in comparison with an equivalent amount of nitrogen 

 from dried blood the experiments with the sludge showed better growth at the 

 end of IS days than those with dried blood and much better than those with 

 no added nitrogen. 



Can sewage sludge be made valuable as a fertilizer? {Engin. Neios, IS 

 (1915), No. 12, p. 593). — Brief reference is made to the experiments noted 

 6318°— No. 5—15 3 



