Abstract
In the evaluation of metal ion shifts the presently available “normal” values are limited by the variability of the methods used in obtaining them and at present can serve as useful guidelines but not as statistical facts. The data of Tipton and Cook on human tissues are reviewed, and it is pointed out that within the limitations of the methods the data provide valuable information. Examples of experimental data illustrating the use of inorganic tissue analysis to elucidate toxic mechanisms are given.