Because of its widespread prevalence, high fatality, and the cause of many current epidemics, diphtheria commands physicians' and the public's attention and concern. Dr. Wilcox acknowledges that there is wide variation in the severity of diphtheria cases, from those severe enough to have no conclusion but death, to those which have been mild enough to make his colleagues hesitant to label as diphtheria.
Dr. Wilcox goes on to describe the history of diphtheria, tracing it back to the Greeks, and along the way, pointing out other instances where it might have been thought to be a different disease, such as croup. He then relates recent epidemics of the disease, especially those in the local region. He surmises the causes of diphtheria which he believes are cold, damp air or "warm and dry weather." However, the well-respected medical journal Lancet claims that the condition of the atmosphere has no bearing on the disease, but rather conditions such as crowded living quarters, deficient nutrition, and exhaustion contribute to the prevalence of the disease. Wilcox states that it must be contagious due to familial infection.
He continues with the symptoms of diphtheria, describing the fever, nausea, husky voice, and coated tongue. The doctor then describes the membrane and its formation over the esophagus and trachea and the possible paralysis that may follow an attack of diphtheria. From here he discusses the diagnosis of diphtheria, especially distinguishing it from croup. He talks about the prognosis under various conditions, and ends with a focus on treatments.