616 EXPERIMENT STATION RECORD. 



[Sewage disposal in Glasgow], J. N. McCunn {Daily Cons, and Trade 

 Rpts. [U. S.], 15 (1912), No. 37, pp. 659, 660).— It is stated that the Glasgow 

 sewage is treated by chemical preciintation, the clarified effluent being dis- 

 charged into tlie River Clyde and the sludge pressed and sold direct or after 

 drying to farmers as a manure. 



The sludge cake direct from the filter presses contains about 68 per cent of 

 water. The wet cake contains, according to analyses reported, 0.52 per cent 

 of nitrogen and 0.54 per cent of phosphoric acid and is valued at $1.68 per ton. 

 The dried cake contains 1.34 per cent of nitrogen and 1.39 per cent of phos- 

 phoric acid and is valued at $4.29 per ton. 



SOILS— FERTILIZERS. 



Soil and climate of very small areas, G. Kraus (Boden tmd EUma auf 

 Kleinsteni Raum. Jena, 1911, pp. VI-\-18Jt, pU. 8, flf/s. 5). — This is an account 

 of a detailed study, extending over 11 years, of the relationships of soil, cli- 

 mate, and plant growth in the region of Karlstadt in the Main Valley, the soils 

 of which are derived from a calcareous triassic formation. The work recorded 

 included examinations of the chemical and physical character of the soil and 

 of the parent rocks from which it was derived, the origin, formation, general 

 character, slope, water content, and temperature of the soil, and especially the 

 relation between the physical properties and slope of the soil and the meteoro- 

 logical conditions immediately above it. 



The more general result of these investigations was to show the variable 

 character of the soil and of the meteorological conditions above it within very 

 small areas. It was found that the calcium carbonate varied widely not only in 

 closely adjacent areas but also at different depths in the soil, and that there 

 was no uniform and constant relation between the calcium carbonate content 

 of the parent rock and that of the resultant soil, the proportion of carbonate 

 being dependent mainly upon the stage of soil weathering. 



A study of the distribution of vegetation with reference to the lime content 

 of the soil showed that many plants generally considered to be lime-loving 

 grew well in soils very poor in lime and vice versa, ilost of the plants were 

 able to live and to reproduce in all of the soils, although the lime content 

 varied in different soils from 1 to 60 per cent. Most of the so-called lime toler- 

 ant plants were xerophytes, and hence their distribution was dependent mainly 

 upon the moi-sture content of the soil. 



It was found that the water content of the soils and of the plants growing 

 upon them varied considerably within very small areas and was not always 

 proportional to the amount of fine earth present, although the water capacity 

 and content of the soils appeared to depend upon their physical structure, and 

 this in turn had a marked influence upon the soil temi)erature. The natural 

 vegetation depended more upon the fine earth and the water content of the 

 soil than upon its chemical composition. With equal fineness, the water con- 

 tent was three times as great on a northern exposure as on a southern slope. 

 Soils covered with leaves or grass contained, however, half as much more water 

 as bare soils. This is ascribed to the action of the cover in reducing the effect 

 of the wind. 



The temperature and moisture of the air of a given area appeared to depend 

 largely upon the temperature of the soil. The soil temperature was not 

 dependent upon the air temperature, but upon the amount of solar heat absoi'bed 

 by the surface soil, and this was in inverse proportion to the fine earth and 

 water content of the soil. As a rule the temperature of the soil was lower in 

 winter and higher during the growing period than that of the air. The fact 



