148 



TRACE ELEMENTS IN ANIMALS 



which died from an unknown cause 3 days after the beginning 

 of the experiment and which was immediately replaced by one 

 from the control group, all the treated animals improved in 

 condition and growth and were stated by the farmer to be the 

 best set of lambs he had seen on the farm where the experiment 

 was carried out. The control animals, on the other hand, rapidly 

 lost condition, four died from pining, and by 4 September many 

 others were in the last stage of the disease. 



Stewart, Mitchell and Stewart also examined on a set of plots, 

 the effect on the cobalt content of soil and herbage which 

 resulted from the application of various quantities of cobalt 

 chloride to the soil, the amounts ranging from \ to 80 lb. of 

 cobalt chloride (CoCl 2 .6H 2 0) per acre, superphosphate to the 

 extent of 2 \ cwt. per acre being used as filling material for the 

 small quantity of cobalt used. Ten weeks after the application 

 of the dressings the total cobalt content of the soil and the 

 amount soluble in dilute acetic acid were determined on each 

 plot as well as the cobalt content of the herbage. The results, 

 given in Table XIX, show how in this comparatively short time 

 the application of cobalt to the soil affects the cobalt content 

 of the herbage. 



Table XIX. Effect of cobalt manuring on the cobalt content 

 of herbage. (Data from Stewart, Mitchell and Stewart) 



The favourable effect on lambs produced by such manuring 

 was shown by another experiment carried out by Stewart, 



