438 University of California Publications in Agricultural Sciences [Vol. 1 



No. 



3887 

 3888 



TABLE XXII 



Cultures in Tailings Soils 



Pot culture Condition 



Corn ill sandy loam Distinctly striped 



Corn in sandy loam Less distinctly 



and tailings striped 



3887 Beans in sandy loam Normal appearance 



3888 Beans in sandy loam Normal appearance 



and tailings 



3887 Squash in sandy loam Yellow and stunted .027 



3888 Squash in sandy loam Normal appearance 



and tailings 



Fig. 12. — Showing- effects of copper modified by tilth of soil. Strong growth, 

 lumpy mixture; weak growth, thoroughly mixed. 



Bean cnlturcs appeared little affected by copper in either 

 Xo. 38S7 or No. 3888 ; but squash was distinctly damaged in 

 No. 3887, being yellow and stunted. The leaves of both cultures 

 of corn were paler tlian those of the check, but in soil No. 3887, 

 containing less copper, the leaves of corn were more distinctly 

 striped than in No. 3888. This is probably due to the sandy 

 character of No. 3887 with consequently decreased adsorptive 

 action upon coppei* salts. Lumpiness in the heavier soil might 

 also account for a lessened toxic action, as indicated by an 

 experiment in which 0.1 per cent of copper in the form of pre- 



