16 gillespie: hydrogen-ion concentration in soils 



results. Such agreements show that the two methods give com- 

 parable results and give ground for inferring that such results 

 are approximately correct. 



CONTINUATION OF EXPERIMENTS 



The experimentation is being continued. Special effort will be 

 made to develop the colorimetric method into a convenient and 

 practical test and to determine its reliability as applied to soils 

 under field conditions. 



