816 EXPERIMENT STATION EECOED. 



more of salicylic aldehj-de prevented any decomposition in the solution. In the 

 solutions with plants it required as much as 50 parts per million of salicylic 

 aldehyde in the mannite solutions to prevent decomposition. ... In every 

 case 25 to 50 parts per million of salicylic aldehyde in nutrient solution with 

 mannite prevented any bacterial action." 



Salicylic aldehyde was harmful to the growth of plants as well as to bacterial 

 life. 



Th.e importance of soil colloids for agriculture and forestry, P. Rohland 

 {Forstw. Centbl, n. ser., 37 {1915), Nos. 6, pp. 257-263; JO, pp. 455-460).— An 

 additional contribution to the subject is given, covering practically the same 

 ground as previous articles (E. S. R., 34, p. 18). 



Colloidal clay, P. Ehrenberg and G. Given (Kolloid Ztsclir., 17 {1915), No. 

 2, pp. 33-37) . — After a brief review of the work of others bearing on the subject, 

 experiments with a highly plastic clay are reported, the results are taken to 

 indicate that the colloids of clay exhibit all the general characteristics of 

 emulsoids. 



Moisture relations of some Texas soils, G. S. Fraps {Texas Sta. Bui. 183 

 {1915), pp. 36, figs. 6). — Two years' studies supplementing experiments pre- 

 viously noted (E. S. R., 33, p. G19) on the moisture content of clay, black clay, 

 loam, sand, clay loam, and black clay loam soils under different conditions and 

 fertility treatments are reported. Curves are given showing the moisture 

 content of the soils at different iieriods and the relation of the moisture to the 

 rainfall. 



It was found that the average quantity of water in soils after continued 

 rains was 58 per cent of the water capacit)' measured in the laboratory, and 

 the maximum quantity was G9 per cent. " The .soils retained when saturated 

 to a depth of 14 in. enough water for from 12.6 to 19.1 bu. of corn, or from 156 

 to 234 lbs. of lint cotton. The crop draws upon a greater depth of soil for 

 moisture, but there are also great losses due to evaporation." 



Both cultivation and manuring increased the quantity of water held at the 

 ends of the wet periods. The soils retained at the ends of the dry periods, on 

 an average of the two years, 44 per cent of the water capacity measured in the 

 laboratory. The lowest quantities reachetl in 1911 were from 33 to 46 per cent 

 of the water capacity; in 1912, from 21 to 41 per cent. Cultivation and 

 manuring increased the water content of the soils at the ends of the dry periods 

 and decreased the loss by evaporation. There was a variation of about 50 

 per cent in the capacity of the various soils to hold water during wot periods 

 and to retain water during dry periods. 



Absorptive power of soils of Mauritius, P. de Sornay {Dept. Agr. Mau- 

 ritius, i>ci. Set:, Bui. 1 {1915) [English Ed."], pp. 18; ahs. in Internet. Inst. 

 Agr. [Rome], Mo. Bui. Agr. Intel, and Plant Diseases, 6 {1915), No. 10, pp. ISOS, 

 130/i). — Two series of experiments with representative soils taken from dilTerent 

 parts of the island of Slauritius are reported, the purpose of which was to 

 determine their ab.sorptivo powers for ammonium sulphate, potassium nitrate, 

 potassium sulphate, sodium nitrate, and calcium superphosphate. The first 

 series consisted of percolation and the second of leaching experiments. Pre- 

 liminary experiments showed that these soils when saturated contained an 

 average of about 40 per cent of water, and that their average moisture content 

 to a depth of 1 ft. was about 19 per cent. 



The results of the main experiments led to the conclusion that the absorption 

 of free or alkaline bases always takes place and that its intensity varies ac- 

 cording to tlie nature of the soil. " In Mauritian soils this absorption of bases 

 is particularly high when the conditions of experiments represent as nearly as 



