EXPERIMENT STATION BULLETINS. 497 



THE SOIL SOLUTION OBTAINED BY THE OIL PRESSURE 



METHOD. 



TECHNICAL BULLETIN NO. 28. 



FOREWORD. 



In my annual report for the year ending June 30, 1913, there appeared 

 a brief account of the efforts of Dr. F. H. H. Van Suchtelen and Mr. 

 Arao Itano to separate from the soil the liquid phase. We encouraged 

 these efforts because we were not satisfied with the results or the promise 

 of results from the then existing lines of research in soil bacteriology, 

 viz. : 



I. Numerical determination of bacteria in soil. 

 II. Determination of species of bacteria in soil. 

 III. Transformation experiments such as involve determinations of 

 ammonia, nitrites, nitrates, etc. 



The soil presents three phases: the solid, the liquid and the gaseous. 

 The study of the soil from any standpoint has always been difficult be- 

 cause of its complexity due- to each of these phases and to their interre- 

 lationships. It has been our thought and purpose to throw some light 

 on the liquid phase and the present paper contains a description of the 

 method of its extraction, devised by Van Suchtelen and Itano, with some 

 of their results, together with more extensive data relative to the chem- 

 ical content and physical properties of the soil solution. It has been 

 our thought that such a preliminary study is a necessary preparation 

 for any biological research with the liquid phase of the soil. A further 

 report, involving the micro-biological aspects of the soil solution, is now 

 undergoing preparation. 



WARD GILTNER. 



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