8 3 6 



Journal of Agricultural Research 



Vol. VI, No. 22 



COMPUTATIONS FROM DATA OF LIPMAN AND WAYNICK 



Ivipman and Waynick report (12, p. 8-9) both the hygroscopic coeffi- 

 cients and the moisture equivalents on 27 samples used in the well- 

 known so-called Tri-State Soil Exchange Experiment, The ratios, 

 which evidently they did not compare, we show in Table II. These 

 data have an added interest in that they are from the laboratory of the 

 late Dr. Hilgard, who introduced the determination of the hygroscopic 

 coefficient (8, 9, 10). 



Table II. — Relation of the moisture equivalent to the hygroscopic coefficient shown by the 



data of Lipman and Waynick 



HYGROSCOPIC COEFFICIENT ' 



MOISTURE EQUIVALENT a 



Average . 



23.64 



22.32 

 22. 20 

 24.24 



22.67 



20. 32 



23-53 



32.61 



33-33 

 30. 21 



29.63 

 30.78 

 27-57 



29.80 

 3.1- if 



23.62 

 24. 26 



29. 17 



23.67 

 26. 02 

 29. 16 



21. 92 

 19-37 



27-38 



RATIO OF MOISTURE EQUIVALENT TO HYGROSCOPIC COEFFICIENT 



Average . 



4.67 



2-53 

 2-97 



1 From Lipman and Waynick (12, p. 8, Table I). 2 Prom Lipman and Waynick (12, p. 9, Table II). 



The average ratio for the 27 samples is 3.08, with a minimum of 2.41 

 and a maximum of 4.67, a range of 93 per cent. On inspection of Tables 

 I and II it will be seen that for the Kansas soils the ratio varies only 

 between 2.49 and 2.76, and for the California soils between 2.41 and 

 3.39, with an average for these 18 samples of 2.72, which is practically 

 identical with the mean found by Briggs and Shantz — viz, 2.71. 



In the case of the 9 samples of Maryland soils, the ratio varies from 

 2.53 to 4.67, with an average of 3.75. As none of the samples is to be 

 considered lighter in texture than a loam or heavier than a clay loam, 

 any ratio sufficiently accurate for ordinary purposes should apply to all 

 of them. 



