AGRICULTURE: E. C. MILLER 
427 
B 
DEGREES 
b R 
VOLTS 
<f> 
VOLTS 
1 
27,200 
2.34 
2.39 
2 
30,100 
2.59 
2.54 
3 
23,500 
2.02 
1.97 
4 
25,200 
2.16 
2.28 
5 
38,200 
3.28 
3.22 
6 
40,600 
3.49 
3.45 
Filaments 1 and 2 were coated with BaO 50%, SrO 25%, CaO 25%, 
Filaments 3 and 4 with BaO 50%, SrO 50%, and Filaments 5 and 6 
with CaO alone. 
It appears that for Wehnelt cathodes the values <f> and bR/e show a 
good correspondence. This is a strong point in favor of the view that 
the emission of electrons from Wehnelt cathodes is due to a similar 
mechanism to that causing the emission from heated pure metals. It 
is also a further proof of the substantial correctness of Richardson's 
hypotheses to account for the emission of electrons by hot bodies. 
DAILY VARIATION OF WATER AND DRY MATTER IN THE 
LEAVES OF CORN AND THE SORGHUMS 
By Edwin C. Miller 
KANSAS AGRICULTURAL EXPERIMENT STATION 
Communicated by R. Pearl, May 14. 1917 
In connection with the study of the water relations of corn and the 
non-saccharine sorghums previously reported by me (/. Agric. Res., 
6, 1916), it was thought advisable to determine the daily variation of 
the water and dry matter in the leaves of these plants. A knowledge of 
the variation of the water in the leaves should throw some light on the 
relative ability of these plants to absorb water from the soil and to trans- 
port it to regions of loss from transpiration, while a study of the daily 
variation of dry matter in the leaves would permit a comparison of the 
relative power of the plants to manufacture food under different climatic 
conditions. The experiments herein reported were conducted during 
the simimers of 1914, 1915, and 1916 at the State Branch Experiment 
Station at Garden City, Kans. 
Cultural Methods. — The plants used in these experiments were Pride 
of Saline corn, BlackhuU kafir and Dwarf milo. In 1914 and 1915, the 
plants were grown in alternate rows on the same plot, while in 1916 the 
experiments were made with plants grown on a series of one twentieth 
acre plots. The plants were growa in a sandy loam soil that had been 
