CONTINENTAL NOTES GERMANY. 21 7 



productive condition of agricultural soils subject to frequent 

 variations, due to annual manuring, changing of crops, etc., 

 could at any time be accurately ascertained, would be even 

 more applicable to the more constant forest soils. 



It seemed, however, desirable to introduce for this purpose 

 certain modifications and simplifications in the application of 

 Remy's method, and Albert studied the problem for a season in 

 the well-known forest plots at Eberswalde, in the vicinity of his 

 central laboratories, before applying the method to the heather 

 regions under investigation. He iselected four pattern plots, and 

 took in each, at two different spots, samples of the soil every 

 month from April to October. He scraped the soil from the 

 walls of freshly dug pits of 30 cm. depth directly into sterilised 

 glasses fitted with glass stoppers, and conveyed these immedi- 

 ately to his laboratory. Here he put 300 grms. of each sample 

 into sterilised sample glasses, and mixed them with 300 cub. 

 cm. of sterilised water. After vigorously shaking the glasses 

 for five minutes, the sand settled almost immediately at the 

 bottom of the glasses, leaving the soil solution above it. This 

 solution was carefully taken out with sterilised syphons and 

 5 cub. cm. of it, representing 5 gms. of soil, were then mixed 

 with 10 cub. cm of a 1-5 °'„ sterilised solution of peptone. This 

 mixture was placed in test glasses within incubators in which 

 a constant and even temperature of 25° centigrade (77^ F.) 

 was automatically maintained. After five days the quantity of 

 separated ammonia was ascertained analytically. 



Fifty-six different analyses were made during the summer ; 

 the results were entirely satisfactory, showing that the intensity 

 of the power of decomposition ascertained by this method was in 

 direct and close relation with the known conditions of the soil of 

 the pattern area. The possibility of making at one and the same 

 time a large number of such analyses, without any considerable 

 increase of labour and time, is of special advantage as regards 

 forest soil, which, as elucidated by Albert's experiments, are but 

 rarely as uniform and homogeneous as the regularly worked up 

 field soils. Dr Albert made many other experiments on Remy's 

 principles in regard to the formation of saltpetre, the intensity of 

 fermentation, etc., and found that all of them were closely bound 

 up with the activity of the soil as regards decomposition. In his 

 subsequent biological investigations he therefore restricted his 

 quantative analysis to this and to the intensity of fermentation. 



VOL. XXVIL PART IL P 



