412 Unirersity of CaUfornia Publications in Agricultural Sciences [Vol. 1 



which is inaxiimuii in heaves and (|uaiititatively small in the 

 fruiting parts of a plant. Additional evidence of this fact is 

 shown in poisoned corn plants, which are discussed on a snhse- 

 quent page. 



Comparing the data of table VII with those of table VI, it is 

 evident that, excluding corn and alfalfa irrigated with C. & A. 

 mine waters, in every case except that of one sample of corn from 

 old Fort Low^ell (No. 3519) the copper in crops grown on Gila 

 Valley farms is nuich in excess of that in plants coming from 

 elsewhere for the same classes of material. The presence of 

 appreciable amounts of copper in samples of alfalfa, corn, barley, 

 and mistletoe also accords with the fact that the soils in which 

 they were grown receive the drainage from copper-bearing w^ater- 

 sheds. The one exception, at Yuma (No. 3515) where no trace 

 of copper could be found either in alfalfa or in soil (No. 3503), 

 indicates that these alluvial river deposits, which have been sub- 

 jected annually to the leaching action of enormous quantities of 

 flood waters, have been prevented from accumulating appreciable 

 quantities of copper. 



Copper in the Flesh .\nd I^ones op a Pig 



In order to follow the copper as far as possible in its trans- 

 migrations, a tive-months-old pig that had been born and brought 

 up in an alfalfa pasture near Solomonville under the Montezuma 

 Ditch, was killed and portions of the flesh and bones were taken 

 for examination, with the following results: 



The largest amount of copper was found in portions of liver, 

 heart and rib meat, only minute amounts being present in the 

 bony material. In this connection, it is stated that about two 

 parts of copper have been observed in one million parts of human 

 liver; ten parts in human kidneys, and as much as fifty parts 



