**Paolo Mazzarello**

Department of Brain and Behavioral Sciences and University Museum System, University of Pavia, 27100 Pavia, Italy; paolo.mazzarello@unipv.it; Tel.: +39-382-984711

Received: 26 February 2020; Accepted: 28 April 2020; Published: 30 April 2020

**Abstract:** Carlo Forlanini (1847–1918), a medical doctor professor at the universities of Turin and Pavia, was the inventor of artificial pneumothorax, a method that allowed a first significant victory in the long war of medicine against pulmonary tuberculosis. The article outlines a portrait of this important clinician and focuses on the therapeutic innovation he introduced for the treatment of this infectious disease.

**Keywords:** Carlo Forlanini; tuberculosis; artificial pneumothorax

#### **1. Annus Mirabilis**

Sometimes it seems that, at certain moments, the lines of history converge in determining radical changes in scientific thought and practice. The year 1882 was certainly one of these for the history of infectious diseases. On March 24 of that year, Robert Koch announced the isolation and identification of *Mycobacterium tuberculosis* as the causative agent of tuberculosis. The session of the Berlin Physiological Society, during which the German medical doctor gave the report on the discovery of this new microorganism, was one of the most dramatic moments in the history of medicine: finally, the elusive nature of one of the main 19th-century scourges found a unitary etiological explanation. Paul Ehrlich (who would be awarded the Nobel Prize for medicine in 1908), present at the time of the conference, always remembered that evening as "the most important scientific experience of my life" [1]. Against all those who still rejected the contagious nature of tuberculosis, invoking constitutional, degenerative, food or toxic explanations, Koch advanced his overwhelming evidence. When the work was published a few weeks later, it quickly became a source of methodological inspiration for new microbiological investigations.

The year 1882 was also a milestone in the history of tuberculosis for a second important contribution, the publication of a revolutionary therapeutic proposal for the cure of pulmonary phthisis, that would have great importance until the discovery of the treatment of the disease with streptomycin: the "therapeutic" or "artificial pneumothorax" conceived by the Italian medical doctor Carlo Forlanini [2–5] in Figure 1.

Formulated at first only as a theoretical hypothesis (one of the few cases in medicine in which the public hypothetical prediction precedes the practical realization), it would go on to become, in the hands of its proponents during the first half of the twentieth century, an invention generally applied to treat many selected cases of phthisis, the wasting disease due to tuberculosis of the lungs. The method was also destined to be depicted by an important literary figure. In Thomas Mann's "Magic Mountain", set in the years immediately preceding the First World War, the group of patients who underwent this treatment—which was at the time the main effective direct therapy—consider themselves as part of a special club. In Mann's words: "They have formed a group, for of course a thing like the pneumothorax brings people together. They call themselves the Half-Lung Club" [6,7]. The novel by the Scottish doctor-writer Archibald Cronin, "The Citadel", also dedicates, from a descriptive point of view, an important and precise space to the treatment with artificial pneumothorax.

**Figure 1.** Carlo Forlanini. University Museum System, University of Pavia, Italy.

The cure continued to be the primary one until the discovery of streptomycin, the first effective antibiotic therapy for tuberculosis infection, introduced in 1943 by the microbiologists Selman Abraham Waksman, Albert Schatz and Elizabeth Bugie. However, pneumothorax did not immediately disappear from the therapeutic possibilities and continued to be used until the 1970s, in those cases where the presence of large lung cavities made patients easily susceptible to stagnation of infectious processes.
