This is a small, simply written text aimed primarily at explaining the purpose and techniques of the common laboratory tests to nurses and office assistants. It should be satisfactory for this limited purpose, but it is disappointing to find very little caution regarding the interpretation of these tests. For example, in the section on hemoglobin determinations there is no statement regarding either the technical error inherent in the test or the variability at different ages. Since the erroneous diagnosis of anemia is repeatedly made by paramedical personnel, this should be stressed. This failure to note the difference between infants and adults recurs throughout the book.