tb. by the late 19th century, 70–90% of the urban populations of europe and north america were infected with the mycobacterium tuberculosis, and about 80% of those individuals who developed active tb died of it. however, mortality rates began declining in the late 19th century throughout europe and the united states. at the time, tuberculosis was called the robber of youth, because the disease had higher death rate among young people. other names included the great white plague and the white death, where the "white" was due to the extreme anaemic pallor of those infected. in addition, tb has been called by many as the "captain of all these men of death". a romantic disease "chopin coughs with infinite grace." —george sand in a letter to madame d'agoult the russian writer anton chekhov, who died of tuberculosis in 1904 it was during this century that tuberculosis was dubbed the white plague, mal de vivre, and mal du siècle. it was seen as a "romantic disease". individuals with tuberculosis were thought to have heightened sensitivity. the slow progress of the disease allowed for a "good death" as those affected could arrange their affairs. the disease began to represent spiritual purity and temporal wealth, leading many young, upper-class women to purposefully pale their skin to achieve the consumptive appearance. british poet lord byron wrote, "i should like to die from consumption", helping to popularize the disease as the disease of artists. george sand doted on her phthisic lover, frédéric chopin, calling him her "poor melancholy angel". in france, at least five novels were published expressing the ideals of tuberculosis: dumas's la dame aux camélias, murger's scènes de la vie de bohème, hugo's les misérables, the goncourt brothers' madame gervaisais and germinie lacerteux, and rostand's l'aiglon. the portrayals by dumas and murger in turn inspired operatic depictions of consumption in verdi's la traviata and puccini's la bohème. even after medical knowledge of the disease had accumulated, the redemptive-spiritual perspective of the disease has remained popular (as seen in the 2001 film moulin rouge based in part on la traviata and the musical adaptations of les misérables). in large cities the poor had high rates of tuberculosis. public-health physicians and politicians typically blamed both the poor themselves and their ramshackle tenement houses (conventillos) for the spread of the dreaded disease. people ignored public-health campaigns to limit the spread of contagious diseases, such as the prohibition of spitting on the streets, the strict guidelines to care for infants and young children, and quarantines that separated families from ill loved ones. scientific advances though removed from the cultural movement, the scientific understanding advanced considerably. by the end of the 19th century, several major breakthroughs gave hope that a cause and cure might be found. one of the most important physicians dedicated to the study of phthisiology was rené laennec, who died from the disease at the age of 45, after contracting tuberculosis while studying contagious patients and infected bodies. laennec invented the stethoscope which he used to corroborate his auscultatory findings and prove the correspondence between the pulmonary lesions found on the lungs of autopsied tuberculosis patients and the respiratory symptoms seen in living patients. his most important work was traité de l'auscultation médiate which detailed his discoveries on the utility of pulmonary auscultation in diagnosing tuberculosis. this book was promptly translated into english by john forbes in 1821; it represents the beginning of the modern scientific understanding of tuberculosis. laennec was named professional chair of hôpital necker in september 1816 and today he is considered the greatest french clinician. laennec's work put him in contact with the vanguard of the french medical establishment, including pierre charles alexandre louis. louis would go on to use statistical methods to evaluate the different aspects of the disease's progression, the efficacy of various therapies and individuals' susceptibility, publishing an article in the annales d'hygiène publique entitled "note on the relative frequency of phthisis in the two sexes". another good friend and co-worker of laennec, gaspard laurent bayle, published an article in 1810 entitled recherches sur la pthisie pulmonaire, in which he divided pthisis into six types: tubercular phthisis, glandular phthisis, ulcerous phthisis, phthisis with melanosis, calculous phthisis, and cancerous phthisis. he based his findings on more than 900 autopsies. in 1869, jean antoine villemin demonstrated that the disease was indeed contagious, conducting an experiment in which tuberculous matter from human cadavers was injected into laboratory rabbits, which then became infected. on 24 march 1882, robert koch revealed the disease was caused by an infectious agent. in 1895, wilhelm röntgen discovered the x-ray, which allowed physicians to diagnose and track the progression of the disease, and although an effective medical treatment would not come for another fifty years, the incidence and mortality of tuberculosis began to decline. 19th-century tuberculosis mortality rate for new york and new orleans deaths/year/1000 people year population white people black people 1821 new york city 5.3 9.6 1830 new york city 4.4 12.0 1844 new york city 3.6 8.2 1849 new orleans 4.9 5.2 1855 new york city 3.1 12.0 1860 new york city 2.4 6.7 1865 new york city 2.8 6.7 1880 new orleans 3.3 6.0 1890 new orleans 2.5 5.9 robert koch robert koch, a prussian physician, discovered the cause of tuberculosis. villemin's experiments had confirmed the contagious nature of the disease and had forced the medical community to accept that tuberculosis was indeed an infectious disease, transmitted by some etiological agent of unknown origin. in 1882, prussian physician robert koch utilized a new staining method and applied it to the sputum of tuberculosis patients, revealing for the first time the causal agent of the disease: mycobacterium tuberculosis, or koch's bacillus. when he began his investigation, koch knew of the work of villemin and others who had continued his experiments like julius conheim and carl salmosen. he also had access to the "pthisis ward" at the berlin charité hospital. before he confronted the problem of tuberculosis, he worked with the disease caused by anthrax and had discovered the causal agent to be bacillus anthracis. during this investigation he became friends with ferdinand cohn, the director of the institute of vegetable physiology. together they worked to develop methods of culturing tissue samples. 18 august 1881, while staining tuberculous material with methylene blue, he noticed oblong structures, though he was not able to ascertain whether it was just a result of the coloring. to improve the contrast, he decided to add bismarck brown, after which the oblong structures were rendered bright and transparent. he improved the technique by varying the concentration of alkali in the staining solution until the ideal viewing conditions for the bacilli was achieved. after numerous attempts he was able to incubate the bacteria in coagulated blood serum at 37 degrees celsius. he then inoculated laboratory rabbits with the bacteria and observed that they died while exhibiting symptoms of tuberculosis, proving that the bacillus, which he named tuberculosis bacillus, was in fact the cause of tuberculosis. he made his result public at the physiological society of berlin on 24 march 1882, in a famous lecture entitled über tuberculose, which was published three weeks later. since 1882, 24 march has been known as world tuberculosis day. on 20 april 1882, koch presented an article entitled die ätiologie der tuberculose in which he demonstrated that mycobacterium was the single cause of tuberculosis in all of its forms. in 1890 koch developed tuberculin, a purified protein derivative of the bacteria. data on experimental inquiry published in deutsche landwirthschafts-zeitung provided immediate practical industry benefits in the form of the tuberculin test as an aide to diagnosis in both sick and healthy cattle. tuberculin proved to be an ineffective means of immunization but in 1908, charles mantoux found it was an effective intradermic test for diagnosing tuberculosis. if the importance of a disease for mankind is measured from the number of fatalities which are due to it, then tuberculosis must be considered much more important than those most feared infectious diseases, plague, cholera, and the like. statistics have shown that 1/7 of all humans die of tuberculosis.— die ätiologie der tuberculose, robert koch (1882) sanatorium movement 1950 census enumeration district map of aibonito, puerto rico, united states, indicating a "tuberculosis sanatorium" to be a special (census) enumeration area the advancement of scientific understanding of tuberculosis, and its contagious nature created the need for institutions to house affected individuals. the first proposal for a tuberculosis facility was made in paper by george bodington entitled an essay on the treatment and cure of pulmonary consumption, on principles natural, rational and successful in 1840. in this paper, he proposed a dietary, rest, and medical care program for a hospital he planned to found in maney. attacks from numerous medical experts, especially articles in the lancet, disheartened bodington and he turned to plans for housing the insane. around the same time in the united states, in late october and early november 1842, dr. john croghan, the owner of mammoth cave, brought 15 tuberculosis patients into the cave in the hope of curing the disease with the constant temperature and purity of the cave air. patients were lodged in stone huts, and each was supplied with a slave to bring meals. one patient, a. h. p. anderson, wrote glowing reviews of the cave experience: ome of the invalids eat at their pavillions while others in better health attend regularly the table d'hote which is very good indeed, having a considerable variety and being almost daily (i've noted but 2–3 omissions) graced with a saddle of venison or other game.— a. h. p. anderson by late january, early february 1843, two patients were dead and the rest had left. departing patients died anywhere from three days to three weeks after resurfacing; john croghan died of tuberculosis at his louisville residence in 1849. hermann brehmer, a german physician, was convinced that tuberculosis arose from the difficulty of the heart to correctly irrigate the lungs. he therefore proposed that regions well above sea level, where the atmospheric pressure was less, would help the heart function more effectively. with the encouragement of explorer alexander von humboldt and his teacher j. l. schönlein, the first anti-tuberculosis sanatorium was established in 1854, 650 meters above sea level, at görbersdorf. three years later he published his findings in a paper die chronische lungenschwindsucht und tuberkulose der lunge: ihre ursache und ihre heilung. brehmer and one of his patients, peter dettweiler, became proponents for the sanatorium movement, and by 1877, sanatoriums began to spread beyond germany and throughout europe. dr. edward livingston trudeau subsequently founded the adirondack cottage sanitorium in saranac lake, new york in 1884. one of trudeau's early patients was author robert louis stevenson; his fame helped establish saranac lake as a center for the treatment of tuberculosis. in 1894, after a fire destroyed trudeau's small home laboratory, he organized the saranac laboratory for the study of tuberculosis; renamed the trudeau institute, the laboratory continues to study infectious diseases. peter dettweiler went on to found his own sanatorium at falkenstein in 1877 and in 1886 published findings claiming that 132 of his 1022 patients had been completely cured after staying at his institution. eventually, sanatoriums began to appear near large cities and at low altitudes, like the sharon sanatorium in 1890 near boston. sanatoriums were not the only treatment facilities. specialized tuberculosis clinics began to develop in major metropolitan areas. sir robert philip established the royal victoria dispensary for consumption in edinburgh in 1887. dispensaries acted as special sanatoriums for early tuberculosis cases and were opened to lower income individuals. the use of dispensaries to treat middle and lower-class individuals in major metropolitan areas and the coordination between various levels of health services programs like hospitals, sanatoriums, and tuberculosis colonies became known as the "edinburgh anti-tuberculosis scheme". twentieth century containment a map of deaths from tuberculosis in washington, d.c. in 1900–1901. at the beginning of the 20th century, tuberculosis was one of the uk's most urgent health problems. a royal commission was set up in 1901, the royal commission appointed to inquire into the relations of human and animal tuberculosis. its remit was to find out whether tuberculosis in animals and humans was the same disease, and whether animals and humans could infect each other. by 1919,