Oswald Theodore Avery was one of the founding fathers of immunochemistry (the study of the chemical aspects of immunology) and a major contributor to the scientific evolution of microbiology. His studies of the pneumococcus virus (causing acute pneumonia) led to further classification of the virus into many distinct types and the eventual identification of the chemical differences among various pneumococci viral strains. His work on capsular polysaccharides and their role in determining immunological specificity and virulence in pneumococci led directly to the development of diagnostic tests to demonstrate circulating antibody. These studies also contributed to the development of therapeutic sera used to treat the pneumonia virus. Among his most original contributions to immunology was the identification of complex carbohydrates as playing an important role in many immunological processes. Avery's greatest impact on science, however, was his discovery that deoxyribonucleic acid (DNA)) is the molecular basis for passing on...