The concept of specific receptors that bind drugs or transmitter substances onto the cell, thereby either initiating biological effects or inhibiting cellular functions, is today a cornerstone of pharmacological research and pharmaceutical development. Yet, while the basic ideas of this concept were first explicitly formulated in 1905 by the Cambridge physiologist John Newport Langley (1852–1925), drug receptors remained hypothetical entities at least until the end of the 1960s. Without doubt, the development of receptor-subtype specific pharmaceuticals—especially the beta-adrenergic receptor antagonist propranolol (introduced in 1965)—promoted the acceptance of the receptor concept in pharmacology. It was only in the 1970s, however, that receptors began to be isolated as specific proteins of the cell membrane and that their composition and conformation began to be explored. During the last twenty years the modern techniques of molecular biology have helped to determine the genetic basis of receptor proteins, to identify their amino acid sequences, and to further elucidate their remarkable structural diversity as well as their similarities and evolutionary relationships. Numerous receptor types and subtypes have since been characterized.

In the drive for the consolidation of professional authority, physicians in the nineteenth century sought to exert control over all associated occupations, and weaken the influence of competitors. Many historians have chronicled this process, as doctors and their associations sought to proscribe or eliminate competitors such as homeopaths, eclectics, chiropractors and Thomsonians. Others have explored how physicians sought to subjugate allied occupations such as nursing, radiation technology and physical therapy. Such studies consider power struggles in two contexts. First, doctors could and wanted to function without the interference of others in the health industry. Second, doctors sought to enforce a power structure that placed them at the top with all the other health care occupations beneath them, dependent upon the activities of the physicians to maintain their livelihoods. In both contexts, external factors and internal exigencies shaped the future identity of all occupational groups.

The campaigns to prevent smallpox in the eighteenth and nineteenth centuries are commonly understood as the first attempts of large-scale state-sponsored medical intervention in society as such. Before the discovery of the cowpox vaccine inoculation with variolous matter—known as variolation—was the most widespread preventive against the disease. This practice was well established in parts of Asia and introduced to Europe by Mary Wortley Montagu from Constantinople in 1721. While variolation achieved some popularity—particularly in Britain—Edward Jenner's discovery of the cowpox vaccine in 1796 intensified the efforts to combat smallpox, and vaccination was introduced to large parts of the world within a few years. Although the spread of immunization against smallpox is commonly described as highly successful, the campaigns also represented an early encounter between an elitist state-sponsored medicine and various forms of popular resistance.

The revolutionary period in France was a time of great turmoil. It affected all aspects of society including medicine. One feature which has received some attention is the concomitant change in language. The adoption of the general term officier de santé (literally “health officer”) to denote all those practising medicine at the time provides a particularly interesting example, which has never been properly studied. The distinguished French historian of medicine, Jean-Charles Sournia, has said that the term deserves special attention, but he devotes no more than half a page to it.

“This is an historic occasion”, announced Francis Crick on 2 June 1966, as he began the opening address of the annual meeting of molecular biologists at Cold Spring Harbor. “There have been many meetings”, he continued, “about the genetic code during the past ten or twelve years but this is the first important one to be held since the code became known.” Such bold pronouncements usually guarantee that an occasion will linger in history's footnotes and never shine centre-page. But, as the first public presentation of the complete genetic code, the moment had some claim to being historically complementary to the publication of James Watson and Crick's first paper in Nature. In April 1953, in fourteen paragraphs and a diagrammatic sketch (contributed by Odile Crick), they had announced—with a minimalism that came more of urgent certainty than of diffidence or reticence—not just a physical structure for DNA, but something far more. “It has not escaped our notice that the specific pairing [of purine and pyrimidine bases] we have postulated immediately suggests a possible copying mechanism for the genetic material.” The trajectory begun in 1953 with the suggestion of “a possible copying mechanism” completed its public arc at Cold Spring Harbor in 1966 with a very specific and (almost) complete table showing the genetic code. The occasion “marked”, as Crick later judged, “the end of classical molecular biology”.