BULLETIN D. 



Absorption of Water-soluble Salts by Different Soil Types. 



Between the time of the earlier studies of Thompson and 

 Way, beginning about 1845 and extending on into the later 

 60 ? s, a large amount of work was done, by various 1 observers, 

 on the absorptive power of soils over substances carried in solu- 

 tion when brought in contact with them and allowed to remain 

 there during different intervals of time under different condi- 

 tions. 



The work done along these lines was very carefully and thor- 

 oughly reviewed by Johnson* in 1873, who then pointed out 

 its practical bearings in a very helpful and masterful way. 



In lines of investigation of the character of those which have 

 been presented in Bulletins B and C this matter of the absorp- 

 tive power of soils could not be left out. of consideration and 

 references have been made to it in speaking of the development 

 of the methods for determining small quantities of various salts 

 in soil solutions. 



ON THE EXTENT OF THE POWER OF SOILS TO ABSORB 

 AMMONIA. 



OBSERVATIONS OF WAY.f 



After making a number of qualitative experiments Way un- 

 dertakes more exact quantitative studies, and first in regard to 

 the absorption of ammonia, in which he uses different soils and 



*How Crops Feed. Edition 1902, pp. 333-361. 



t Journal Royal Agricultural Society of England, Volume II, 1850, pp. 313-379. 



