120 LIFE: ITS NATURE AND ORIGIN 



citrus leaf mottle in California, South Africa, and Florida, little leaf 

 of apples and other deciduous fruits in the West and Northwest, and 

 white bud of corn on the Norfolk and Hernando fine sands of Florida; 

 boron cures internal browning of cauliflower and dry rot of sugar beets 

 in Michigan, crown rot of sugar beets in Ireland, die-back of citrus in 

 Africa, internal cork and drought spot of apples in British Columbia, 

 West Virginia and elsewhere, and cracked stem of celery in Florida; 

 copper, added to muck soils in Holland and parts of western New 

 York and to organic soils of Florida, improves the growth of several 

 crops; sulfur corrects yellows of tea in Nyasaland (Africa), and im- 

 proves the growth of field crops in Oregon and other areas. 



Since animals depend upon plants, "the soil is the mother of all 

 living things." Deficiency of cobalt 50 in certain New Zealand soils 

 causes "bush sickness" in sheep, which seems identical with the "pine" 

 of sheep in Scotland. Iodine deficiency leads to goiter in man and 

 beast and caused an annual loss of thousands of pigs in Montana until 

 iodine feeding was practiced. Selenium, taken from the soil by 

 plants, causes disease and malformations in animals eating the plants. 51 

 Marco Polo, on his journey to Tartary, observed hoof deformations of 

 this type, which may have had the same kind of origin. According to 

 A. L. Moxon traces of arsenic compounds, fed in water or in salt, tend 

 to protect animals against the toxic action of selenium, while bromo- 

 benzene aids in its excretion. 



The eighth scientific meeting of the Nutrition Society held in Lon- 

 don, England, Oct. 17th, 1942, was devoted to "Trace Elements in 

 Relation to Health." Among the rarer deficiency diseases mentioned 

 were: enzootic ataxia (swayback of lambs), which may be prevented 

 by feeding traces of copper during pregnancy; molybdenosis (called 

 teart of Somerset), which affects ruminants, due to molybdenum taken 

 up by plants where the soil content of molybdenum was about 100 

 ppm, and helped by traces of copper sulfate; fluorosis, which may 

 cause osteosclerosis, though teeth with mottled enamel due to fluorine 

 are relatively immune to decay. 



It must not be supposed that trace substances always operate in one 

 way, for the complications in any case may be great. Thus sulphur 

 may be oxidized by soil bacteria and affect the local pH — from which 

 a chain of other consequences may follow. However, much of the 

 evidence points to the conclusion that the inclusion of trace substances 

 in catalyst surfaces is a frequent factor that must always be considered; 

 for visible results develop from the products of catalysis. 



Chemical Activators 



A great mass of evidence has accumulated to indicate that many 

 important biological changes are directed, or powerfully influ- 



