Medieval thermalism and at the beginning of the Renaissance

Medieval thermal infrastructures are little known, but it seems that baths were used since the early Middle Ages, starting from the ancient Roman baths.[7]​ Pleasure baths gained importance during the 1st century, when the popes practiced them (recreatio corporis).[8]​ The first thermal regulations were issued by the main city-states of Tuscany, Lazio and Emilia-Romagna. Its objective was to ensure public possession and control of the mainly hot and mineral waters, which were no longer considered "miraculous waters", but rather "curiosities and wonders of nature." The first cities to define thermal spaces were Siena, Bologna, Volterra, Lucca, Florence and Pisa.[9]​.

For this purpose, the municipal authorities created bathtubs, ponds or swimming pools surrounded by walls and without roofs, accompanied by buildings. Some fountains were dedicated to bloodshed (made by leeches), other pools were reserved for women or lepers. Later, lepers were placed in baths and then sent to dry in the sun to enhance their healing. War wounded also gathered in the thermal baths to recover.

In addition to the care of the most diverse ailments, some sites were associated with sacred places, others with places of sexual license and prostitution.[7]​.

Accommodation in baths is attested since the 19th century, especially near Siena, first in camps, then in buildings, and finally in hostels.

The first medical works on mineral and therapeutic waters appeared in Italy at the end of the century, in Germany in the century, and in France, Switzerland, England, in the century and then throughout Europe. The most important Italian doctors in this field were Gentile da Foligno"), Ugolino da Montecatini"), Michel Savonarole") and Andrea Bacci"). These texts presented the mineral components of thermal waters and their use according to the diseases and the type of patient[9]​ (according to the principles of Galenism). This first thermal medicalization tended to impose practical rules of use, which were not really controlled by doctors on the spot, but rather more or less applied, by "self-control",[10]​ by cultivated curists.

The first rule was the thermal season: the cure at a spa required a stay of several weeks during the favorable months, which varied depending on the location (most often warm and temperate months). Before the 19th century, most Italian and German sites were open ponds or pools. The duration and modalities of the stays depended on the diseases to be treated. The other rules concerned body techniques that differed from the initial baths: showers, drinks and specific living regimens. These new practices first appeared in Tuscan sites beginning with the Italian Renaissance.[8]​.

The oldest drinking fountains were used at the end of the century: Bagno di Montecatini, della Poretta, di Bormio. One of the most famous was Bagno della Villa, near Lucca,[11] destination of Michel de Montaigne during his trip to Italy.

These regulated cures opposed behaviors considered too licentious (good food, alcohol and sex) but also proposed the need for entertainment to keep the soul happy in a relaxing society. The great figures who came for treatment were not only accompanied by their doctor, but also by courtiers, artists (painters, musicians, poets) and jesters who needed to be accommodated and entertained.

The courts of Europe had their spies in all the places of priests to find out who was there.[12] The thermal sites were at the same time a form of encounter, a pretext for distancing without breaking, of temporary retreat or retreat. During the 19th century, trips and stays in baths were also a means of social, political or diplomatic maneuvers.[13]​.

Outside Italy, the most famous sites of this period were Baden "Baden (Aargau)") and Pfäfers in Switzerland, Cauterets and Bagnères in France, Plombières in Lorraine, Spa "Spa (Belgium)") in Belgium. In general, these thermal resorts were characterized by a lack of comfort in the stay, even for the most famous ones (Montaigne complains about this).[7]​.

During the Muslim domination of the Iberian Peninsula (711-1492), the bathing culture was maintained and significantly enriched. The Arabs established numerous hammams in the cities, especially in Al-Andalus. Muslim Córdoba once had up to 600 public bathrooms.[14]​.

Place names such as Alhama de Granada, Alhama de Murcia, Alhama de Aragón or Caldas de Reis testify to this heritage (Al-Hammam means "the baths" in Arabic, while Caldas derives from the Latin Aquae Calidae). After the Reconquest, many Arab baths were abandoned or converted, although some springs maintained their medicinal use under ecclesiastical or royal control.

Unlike other European countries, in Spain the thermal tradition was never completely interrupted. Towns such as Caldas de Montbui, Alhama de Murcia or Archena maintained continuous use of their waters from Roman times, through the Muslim period to the present day. The Charter of Cuenca (1189-1190) already regulated the use of public baths, and the Siete Partidas of Alfonso X the Wise included provisions on medicinal baths.

Thermalism in Spain

Modern thermalism in Spain began with the Royal Decree of Ferdinand VII of June 29, 1816, which created the Corpo de Médicos de Baños (Corpo de Médicos Directores de Baños), with administrative, investigative and clinical functions in the most frequented Spanish spas.[15]​.

In 1817 the Regulation of the mineral waters and baths of Spain was issued, which ordered that the Bath Doctors supervise the thermal facilities, attend to the bathers and prepare an annual report with clinical and analytical observations. Between 1816 and 1936, more than 100 springs of public utility were declared in Spain.

On February 23, 1877, the Spanish Society of Medical Hydrology (SEHM), one of the oldest medical-scientific societies in Spain, was founded, with Benigno Villafranca") as general secretary and José Salgado y Guillermo") as president.[16]​.

The second half of the century and the beginning of the century marked the golden age of Spanish thermalism. Spas such as Mondariz (declared Villa Termal in 1873, the only one with its own municipality), Archena, Panticosa, Cestona, Solares or Hervideros de Cofrentes (1902) became meeting centers for the European aristocracy and bourgeoisie.[17]​.

The large hotel complexes competed with the best European establishments: the Balneario de La Toja with its Gran Hotel (1907), Mondariz with its pioneering bottling plant (1874), Archena with its casino (1898), and Panticosa, which achieved international recognition. Royalty and intellectuals frequented these centers: Alfonso XIII in Betelu, Queen Victoria Eugenia in La Toja, while Santiago Ramón y Cajal, Emilia Pardo Bazán and Benito Pérez Galdós were regular visitors.

Spanish spa architecture of the period combines neoclassical, modernist and regionalist elements. Highlights include the modernist pavilion of the Vichy Catalán Spa (1901), the galleries of Cestona and Puente Viesgo, and the neo-Mudejar buildings of Alhama de Aragón. Many had theaters, casinos, chapels and gardens designed by architects such as Lluís Domènech i Montaner or later Miguel Fisac.

The architecture of the Spanish spas of the century combines neoclassical, modernist and regionalist elements. Ejemplos notables incluyen el pabellón modernista del Balneario Vichy Catalán (1901), la galería de baños del Balneario de Panticosa (1854), o el edificio neomudéjar del Balneario de Alhama de Aragón (1880). Many were designed by renowned architects such as Lluís Domènech i Montaner or Miguel Fisac.

On January 5, 1912, by Royal Decree, the Chair of Medical Hydrology was created at the Central University of Madrid (current Complutense University of Madrid), academically institutionalizing the discipline.[18]​ The chair continues to be active, being, together with the University of Santiago de Compostela, the only Spanish centers where this specialty is taught.

Since 1989, the Institute for the Elderly and Social Services (IMSERSO) has managed the Social Thermalism Program, which facilitates access to thermal treatments for people over 60 years of age and pensioners. This program, unique in Europe due to its extension, benefits more than 200,000 people annually and has been fundamental for the survival and modernization of the Spanish spa sector.[19]​.

The program includes treatments in more than 100 spas distributed throughout Spain, with special concentration in Galicia (21 spas), Catalonia (19), Aragon (13), Andalusia (11) and the Valencian Community (4).

In addition to the Complutense and Santiago universities, other Spanish institutions carry out research in medical hydrology. The Geological and Mining Institute of Spain (IGME) maintains an updated inventory of all mineral-medicinal waters in the country.[20] The National Association of Spas (ANBAL), founded in 1947, brings together more than 50 establishments and promotes scientific research.

Several Spanish spas are classified as Assets of Cultural Interest:.

France developed an important thermal administration since the 19th century. In 1605, Henry IV created the Charte des eaux minérales and the position of general superintendent of mineral waters. During the 19th century, cities such as Vichy, Bourbon-l'Archambault and Forges-les-Bains became important thermal centers. French thermalism influenced the development of the sector throughout Europe.

Following the interested advice of Jean de la Rivière,[21] Henry IV created the Charte des eaux minérales [Charter of mineral waters], the legal basis[22]​ of a regulation and a new thermal administration created by appointing at its head a general superintendent of the Mineral Waters of France, Jean de la Rivière himself (Edict of May 1605). This administration was primarily made up of mayors who managed water at the level of a province or a region. It then became customary to appoint an administrator for each major resort, and during the century for medium-sized resorts.

These mayors were doctors who specified the development and modalities of the cures, ensuring the quality of the water and the cleanliness of the bathrooms. The mayor directed other doctors, the bathers (personnel assigned to bathrooms) and the plumbers (personnel assigned to drinking water). The mayor had to present an annual management report to the general superintendent. During the 19th century, few stations saw real attendance: Bourbon-l'Archambault, Vichy, Forges, Barèges.[23]​.

The army contributed strongly to the development of certain spas such as Bourbonne-les-Bains (Haute-Marne), since Louis XV and given that this small town already had a thermal past in Roman times. Thus, a military hospital cared for wounded soldiers in that wine-growing town (350 hectares) which thus found an excellent outlet for its wines.

Meanwhile, in 1685, a royal edict restricted the freedom to extract water for free, transport it and market it, in order to preserve its quality against fraud and counterfeiting. Throughout the century, the use of mineral waters became increasingly regularized (declaration of April 25, 1772, Council ruling of May 12, 1775, declaration of May 26, 1780...) inscribing mineral waters in a pharmaceutical and medical logic. Large cities established a "Bureau des eaux minérales" (Mineral Water Office) responsible for controlling the patents, quality and trade of waters: Paris (1716), Marseille (1739), Bordeaux (1745), Montpellier (1753), Toulouse (1762).

Thermal medicine was known by the consilia, in Latin, then by the consultations (consultations) in French, in writings from the century to the beginning of the century. These are collections handwritten or printed by thermal doctors during their practices. French doctors were mainly in the south of the country, centered on Montpellier. This thermalism only affected a small minority of wealthy patients with less severe pathological conditions or sequelae.

The doctrines did not refer to ancient or medieval authorities, they were based mainly on empirical habits of use and the personal experience of the doctor. The medical discourse was adapted according to the currents of the moment: to Galenism with "refreshing" and "moisturizing" waters against excesses of heat and dryness, then to the mechanism "Mechanism (philosophy)") with "diluting" and "fluidifying" waters against viscosities and obstructions, and finally to vitalism with "tonifying" waters against weakening. It would be a subjective and imaginary discourse to compare with a poetic context studied by Bachelard in L'eau et les rêves")[24]​ [Water and dreams]..

The development of medical thermalism in France was the work of the king's doctors. The very lucrative position of general superintendent of the baths, created in 1605, automatically fell to the king's first physician in 1709. According to J. Coste, medical thermalism was a route to social advancement towards nobility, the dream of many doctors under the Ancien Regime. The thermal administration was, therefore, a place of complicity, of links of interests and family strategies, an example of success being that of Théophile de Bordeu.[25]​.

The most famous spas in Central Europe were in the Principality of Liège - with Spa "Spa (Belgium)") notable for its cold waters -, in the Duchy of Nassau - with Schwalbach - for its mineral waters, Wiesbaden for its warm waters or Schlangenbad for its warm waters -, in the free city of Aachen, known for its very hot waters. In Switzerland, they were the resorts of Aargau, with Schintznach and Baden "Baden (Aargau)"), famous for its sulfur waters.

Those stations had open-air public baths, covered private baths, and stoves and steam baths. The waters were drunk directly from the source from dawn. The care provided by the Germans and Swiss was characterized by extensive use of suction cups. Most chronic diseases and the consequences of injuries were treated, with the exception of chest diseases.

During the century, a literary genre about baths (Amusements des eaux) developed in Germany, written in French, the international language of the time. They were above all advice guides, then tourist guides, travel stories, manuals of good manners, mixing gallant anecdotes between curists and erudite controversies about water.[26]​.

Germanic thermalism was thermal tourism for European elites, for nobles and bourgeois, based on the reputation of the waters, the quality of care and the enjoyment of the stay. The entertainment was numerous: walks, picnics, excursions, game rooms (billiards), games of chance (Pharaoh&action=edit&redlink=1 "Pharaoh (game) (not yet written)")), lotteries, dances, concerts and shows... The mundane life of the spa brought together both sexes in a more intimate way than in their usual meeting place, each being able to talk more easily about the other's body and health. According to a text from the time, "it seems that in Aix [Aix-la-Chapelle] being sick or being gallant are the same thing."[27]

This thermal pleasure for wealthy people gave rise to many professions, with beneficial effects on the local and regional economy of the thermal areas. It also attracted thieves and adventurers. According to E. Belmas, this thermalism represented the beginnings of a leisure industry, a luxury trade, and also that of counterfeits, souvenirs and trinkets.[26]​.

The most renowned station in England was Bath, followed by Tunbridge Wells, Buxton "Buxton (Derbyshire)"), Scarborough&action=edit&redlink=1 "Scarborough (Yorkshire du Nord) (not yet drafted)") and Cheltenham. As in Germany, these stations offered leisure and entertainment to aristocrats and gentry, generating important commercial activity. These stations were owned by individuals or private corporations, outside the guardianship of the Crown or the Church. Local businessmen freely exploited the growing taste of the English bourgeoisie for luxury and consumption, eager to buy health and leisure at the same time and in one place.[7]​.

Mineral waters were bottled: those rich in iron were used as purgatives; those of Bath to treat infertility. Doctors patented the waters as medicines, as Nehemiah Grew did for the salts of Epsom waters (rich in magnesium sulfates). This gave rise to a medical literature that was both a scientific study and a commercial prospectus.[7]​.

Portugal has a rich thermal tradition with more than 40 active thermal stations. Caldas da Rainha, founded by Queen Leonor of Viseu in 1485, was the first thermal hospital in the world. Other historical centers include Vidago, Caldas de Monchique") and the Termas de São Pedro do Sul").

Italy, direct heir to Roman tradition, maintains more than 380 thermal establishments. Montecatini Terme, Abano Terme and Salsomaggiore Terme are internationally recognized. The Tuscany region concentrates the largest number of natural thermal springs in Europe.

The waters of the Belle Époque

Thermalism will experience exceptional development in the 20th century, carried by the wave of romanticism in Europe.

For reasons of ease of access, the first thermal resorts were developed earlier in the vicinity or in the interior of large cities. But very soon, the rapid extension of railway links will make isolated stations accessible to Parisians and foreigners.[28] The growth in attendance will take off and will go from 22,000 curists in 1822 to 120,000 in 1855. In Savoy, in Aix-les-Bains, personalities from the political and artistic world, including writers, came to the city to take advantage of the thermal waters and made the city one of the most famous seaside resorts in the world.[5]​ On the borders of Lorraine, half a dozen tourist resorts were being developed such as Plombières-les-Bains, the city of a thousand balconies, Vittel, Contrexéville, Bourbonne-les-Bains, Bains-les-Bains...

In the Pyrenean chain no less than 31 thermal stations will be developed, driven by the imperial taste for water cities. Auvergne was no exception to this movement; Le Mont-Dore"), Royat, La Bourboule, Saint-Nectaire... and above all Vichy, which became the archetype of the thermal village par excellence.

At the beginning of the century, hot springs were defined by their temperature (spring water over 20 degrees), but that norm was changing and any natural mineral water with the appearance of being healing will be called "thermal." The thermal station did not have a medical definition, the term came from common language that designated a stop or pause for public vehicles and then for trains. The law of April 13, 1910 defined a spa as a municipality, fraction or group of municipalities that had mineral springs or an establishment that exploited them. This tautological definition confirms the fait accompli of an already established use. In 1912, the number of these stations was estimated at almost 110 in France.[29]​.

After the Revolution, the Académie nationale de médecine inherited the prerogatives of the Académie royale de médecine, including the supervision of mineral waters. However, their role was limited to recommending that doctors supervise thermal cures. In fact, it was the thermal doctors who ensured the promotion of thermal spas. The century saw the emergence of a medical current that was skeptical or critical of thermalism, which was criticized for the relationships of interest of thermal doctors, the absence of recognized scientific bases, imprecise therapeutic indications and unclear results.

For example, the composition of the waters and their classifications remained uncertain. The first was according to temperature, then those of iatrochemistry and protochemistry (chemistry before Lavoisier). They could be classified according to their dominant chemical element, or as a minor but essential element (copper, arsenic, iron...) or trace element, or even according to their therapeutic use. The link between chemical composition and therapeutic effect remained approximate. The discovery of radioactivity relaunched for a time the study of so-called indeterminate mineral waters (without significant composition), but of consecrated therapeutic use.

To respond to these criticisms, thermal medicine evolved and was rationalized. Until then, thermal resorts were universal treatments and treated many ailments in endless lists. Little by little they specialized, based on more precise therapeutic indications (one or two main indications, and a small number of secondary indications). For example, Vichy for metabolic and digestive diseases, sometimes anemic and kidney diseases; other stations treated osteoarticular, respiratory, dermatological conditions... The stations could stand out and gain their identity, covering the national territory with all pathologies.[29]​ This specialization of stations is specific to France, and does not exist in other countries.[30]​.

Thermalism thus led to debates with multiple facets: scientific, institutional, economic and political. Crenotherapy,[31]​[Note 1]​ made its entry into the university from the 1890s with courses in Toulouse and Bordeaux where the first chairs of medical hydrology were created in these two cities in 1922. In 1939, nine medical faculties already had a chair of hydrology (in addition: Paris, Lyon, Lille, Nancy, Montpellier, Strasbourg and Algiers).[29]​.

According to the imperial decree law of France of January 28, 1860 regulating thermal establishments, the use of the waters did not depend on a medical prescription, and nothing obliged the curist to consult a doctor on the spot. Only medical advice was recommended, the objective was the prosperity of the spa. The cures were thus carried out freely: masseuses, bath staff and hotel staff, in search of tips, played the role of guide-advisors in their progress. The thermal doctors were divided between the need to leave complete freedom to the curists to attract them (curists-tourists) and the desire for greater power (over the curists-patients), or even local political power within the municipality.[32]​.

The political debate was related to the strategy: base the cure on the exclusive use of water (medical thermalism) or also on everything around it (tourist or leisure thermalism). This debate reflected an opposition between the French model (centralized and medicalized) and the German model (decentralized and fun). Firstly, the German model seemed exemplary for its remarkable organization of leisure activities. But after the defeat of 1871, a patriotic reaction highlighted the superiority of French thermalism for its superior quality waters and its most specialized and virtuous spas. But French spas had to be modernized to become more attractive, now past the time when thermal sites received donations during royal or princely visits. Economic imperatives led to approaching the German model with the introduction of taxes on gambling and stays.[34]​.

The legal status of gambling&action=edit&redlink=1 "Casino (place) (not yet drafted)") was confusing: prohibited in 1781, authorized in spas in 1806, authorization repealed in 1836. In reality, there were 150 gambling establishments at the beginning of the 20th century in a situation of "illegal tolerance." Several laws, in 1907, reaffirmed the privilege of seasonal cities (spa and thermal baths) in matters of gambling and gambling taxes. In 1910, a law allowed resorts to charge a tourist tax, although this possibility was hardly applied by city councils, for fear of scaring away clientele.

In 1919, the taxe de séjour (tourist tax) became mandatory and an additional tax was introduced to finance the Office National du Tourisme (founded 1910) and the Institut d'Hydrologie et de Climatologie de Paris (founded 1913). In 1939, of more than a hundred listed spas in France, 75 were officially classified, by law, as 'station hydrominérale" (hydromineral station). The development of French spas at the beginning of the century appears as a desire to surpass Germany and one of the means that France put into practice to emerge as an important tourist country.[34]​.

Medieval thermalism and at the beginning of the Renaissance

Medieval thermal infrastructures are little known, but it seems that baths were used since the early Middle Ages, starting from the ancient Roman baths.[7]​ Pleasure baths gained importance during the 1st century, when the popes practiced them (recreatio corporis).[8]​ The first thermal regulations were issued by the main city-states of Tuscany, Lazio and Emilia-Romagna. Its objective was to ensure public possession and control of the mainly hot and mineral waters, which were no longer considered "miraculous waters", but rather "curiosities and wonders of nature." The first cities to define thermal spaces were Siena, Bologna, Volterra, Lucca, Florence and Pisa.[9]​.

For this purpose, the municipal authorities created bathtubs, ponds or swimming pools surrounded by walls and without roofs, accompanied by buildings. Some fountains were dedicated to bloodshed (made by leeches), other pools were reserved for women or lepers. Later, lepers were placed in baths and then sent to dry in the sun to enhance their healing. War wounded also gathered in the thermal baths to recover.

In addition to the care of the most diverse ailments, some sites were associated with sacred places, others with places of sexual license and prostitution.[7]​.

Accommodation in baths is attested since the 19th century, especially near Siena, first in camps, then in buildings, and finally in hostels.

The first medical works on mineral and therapeutic waters appeared in Italy at the end of the century, in Germany in the century, and in France, Switzerland, England, in the century and then throughout Europe. The most important Italian doctors in this field were Gentile da Foligno"), Ugolino da Montecatini"), Michel Savonarole") and Andrea Bacci"). These texts presented the mineral components of thermal waters and their use according to the diseases and the type of patient[9]​ (according to the principles of Galenism). This first thermal medicalization tended to impose practical rules of use, which were not really controlled by doctors on the spot, but rather more or less applied, by "self-control",[10]​ by cultivated curists.

The first rule was the thermal season: the cure at a spa required a stay of several weeks during the favorable months, which varied depending on the location (most often warm and temperate months). Before the 19th century, most Italian and German sites were open ponds or pools. The duration and modalities of the stays depended on the diseases to be treated. The other rules concerned body techniques that differed from the initial baths: showers, drinks and specific living regimens. These new practices first appeared in Tuscan sites beginning with the Italian Renaissance.[8]​.

The oldest drinking fountains were used at the end of the century: Bagno di Montecatini, della Poretta, di Bormio. One of the most famous was Bagno della Villa, near Lucca,[11] destination of Michel de Montaigne during his trip to Italy.

These regulated cures opposed behaviors considered too licentious (good food, alcohol and sex) but also proposed the need for entertainment to keep the soul happy in a relaxing society. The great figures who came for treatment were not only accompanied by their doctor, but also by courtiers, artists (painters, musicians, poets) and jesters who needed to be accommodated and entertained.

The courts of Europe had their spies in all the places of priests to find out who was there.[12] The thermal sites were at the same time a form of encounter, a pretext for distancing without breaking, of temporary retreat or retreat. During the 19th century, trips and stays in baths were also a means of social, political or diplomatic maneuvers.[13]​.

Outside Italy, the most famous sites of this period were Baden "Baden (Aargau)") and Pfäfers in Switzerland, Cauterets and Bagnères in France, Plombières in Lorraine, Spa "Spa (Belgium)") in Belgium. In general, these thermal resorts were characterized by a lack of comfort in the stay, even for the most famous ones (Montaigne complains about this).[7]​.

During the Muslim domination of the Iberian Peninsula (711-1492), the bathing culture was maintained and significantly enriched. The Arabs established numerous hammams in the cities, especially in Al-Andalus. Muslim Córdoba once had up to 600 public bathrooms.[14]​.

Place names such as Alhama de Granada, Alhama de Murcia, Alhama de Aragón or Caldas de Reis testify to this heritage (Al-Hammam means "the baths" in Arabic, while Caldas derives from the Latin Aquae Calidae). After the Reconquest, many Arab baths were abandoned or converted, although some springs maintained their medicinal use under ecclesiastical or royal control.

Unlike other European countries, in Spain the thermal tradition was never completely interrupted. Towns such as Caldas de Montbui, Alhama de Murcia or Archena maintained continuous use of their waters from Roman times, through the Muslim period to the present day. The Charter of Cuenca (1189-1190) already regulated the use of public baths, and the Siete Partidas of Alfonso X the Wise included provisions on medicinal baths.

Thermalism in Spain

Modern thermalism in Spain began with the Royal Decree of Ferdinand VII of June 29, 1816, which created the Corpo de Médicos de Baños (Corpo de Médicos Directores de Baños), with administrative, investigative and clinical functions in the most frequented Spanish spas.[15]​.

In 1817 the Regulation of the mineral waters and baths of Spain was issued, which ordered that the Bath Doctors supervise the thermal facilities, attend to the bathers and prepare an annual report with clinical and analytical observations. Between 1816 and 1936, more than 100 springs of public utility were declared in Spain.

On February 23, 1877, the Spanish Society of Medical Hydrology (SEHM), one of the oldest medical-scientific societies in Spain, was founded, with Benigno Villafranca") as general secretary and José Salgado y Guillermo") as president.[16]​.

The second half of the century and the beginning of the century marked the golden age of Spanish thermalism. Spas such as Mondariz (declared Villa Termal in 1873, the only one with its own municipality), Archena, Panticosa, Cestona, Solares or Hervideros de Cofrentes (1902) became meeting centers for the European aristocracy and bourgeoisie.[17]​.

The large hotel complexes competed with the best European establishments: the Balneario de La Toja with its Gran Hotel (1907), Mondariz with its pioneering bottling plant (1874), Archena with its casino (1898), and Panticosa, which achieved international recognition. Royalty and intellectuals frequented these centers: Alfonso XIII in Betelu, Queen Victoria Eugenia in La Toja, while Santiago Ramón y Cajal, Emilia Pardo Bazán and Benito Pérez Galdós were regular visitors.

Spanish spa architecture of the period combines neoclassical, modernist and regionalist elements. Highlights include the modernist pavilion of the Vichy Catalán Spa (1901), the galleries of Cestona and Puente Viesgo, and the neo-Mudejar buildings of Alhama de Aragón. Many had theaters, casinos, chapels and gardens designed by architects such as Lluís Domènech i Montaner or later Miguel Fisac.

The architecture of the Spanish spas of the century combines neoclassical, modernist and regionalist elements. Ejemplos notables incluyen el pabellón modernista del Balneario Vichy Catalán (1901), la galería de baños del Balneario de Panticosa (1854), o el edificio neomudéjar del Balneario de Alhama de Aragón (1880). Many were designed by renowned architects such as Lluís Domènech i Montaner or Miguel Fisac.

On January 5, 1912, by Royal Decree, the Chair of Medical Hydrology was created at the Central University of Madrid (current Complutense University of Madrid), academically institutionalizing the discipline.[18]​ The chair continues to be active, being, together with the University of Santiago de Compostela, the only Spanish centers where this specialty is taught.

Since 1989, the Institute for the Elderly and Social Services (IMSERSO) has managed the Social Thermalism Program, which facilitates access to thermal treatments for people over 60 years of age and pensioners. This program, unique in Europe due to its extension, benefits more than 200,000 people annually and has been fundamental for the survival and modernization of the Spanish spa sector.[19]​.

The program includes treatments in more than 100 spas distributed throughout Spain, with special concentration in Galicia (21 spas), Catalonia (19), Aragon (13), Andalusia (11) and the Valencian Community (4).

In addition to the Complutense and Santiago universities, other Spanish institutions carry out research in medical hydrology. The Geological and Mining Institute of Spain (IGME) maintains an updated inventory of all mineral-medicinal waters in the country.[20] The National Association of Spas (ANBAL), founded in 1947, brings together more than 50 establishments and promotes scientific research.

Several Spanish spas are classified as Assets of Cultural Interest:.

France developed an important thermal administration since the 19th century. In 1605, Henry IV created the Charte des eaux minérales and the position of general superintendent of mineral waters. During the 19th century, cities such as Vichy, Bourbon-l'Archambault and Forges-les-Bains became important thermal centers. French thermalism influenced the development of the sector throughout Europe.

Following the interested advice of Jean de la Rivière,[21] Henry IV created the Charte des eaux minérales [Charter of mineral waters], the legal basis[22]​ of a regulation and a new thermal administration created by appointing at its head a general superintendent of the Mineral Waters of France, Jean de la Rivière himself (Edict of May 1605). This administration was primarily made up of mayors who managed water at the level of a province or a region. It then became customary to appoint an administrator for each major resort, and during the century for medium-sized resorts.

These mayors were doctors who specified the development and modalities of the cures, ensuring the quality of the water and the cleanliness of the bathrooms. The mayor directed other doctors, the bathers (personnel assigned to bathrooms) and the plumbers (personnel assigned to drinking water). The mayor had to present an annual management report to the general superintendent. During the 19th century, few stations saw real attendance: Bourbon-l'Archambault, Vichy, Forges, Barèges.[23]​.

The army contributed strongly to the development of certain spas such as Bourbonne-les-Bains (Haute-Marne), since Louis XV and given that this small town already had a thermal past in Roman times. Thus, a military hospital cared for wounded soldiers in that wine-growing town (350 hectares) which thus found an excellent outlet for its wines.

Meanwhile, in 1685, a royal edict restricted the freedom to extract water for free, transport it and market it, in order to preserve its quality against fraud and counterfeiting. Throughout the century, the use of mineral waters became increasingly regularized (declaration of April 25, 1772, Council ruling of May 12, 1775, declaration of May 26, 1780...) inscribing mineral waters in a pharmaceutical and medical logic. Large cities established a "Bureau des eaux minérales" (Mineral Water Office) responsible for controlling the patents, quality and trade of waters: Paris (1716), Marseille (1739), Bordeaux (1745), Montpellier (1753), Toulouse (1762).

Thermal medicine was known by the consilia, in Latin, then by the consultations (consultations) in French, in writings from the century to the beginning of the century. These are collections handwritten or printed by thermal doctors during their practices. French doctors were mainly in the south of the country, centered on Montpellier. This thermalism only affected a small minority of wealthy patients with less severe pathological conditions or sequelae.

The doctrines did not refer to ancient or medieval authorities, they were based mainly on empirical habits of use and the personal experience of the doctor. The medical discourse was adapted according to the currents of the moment: to Galenism with "refreshing" and "moisturizing" waters against excesses of heat and dryness, then to the mechanism "Mechanism (philosophy)") with "diluting" and "fluidifying" waters against viscosities and obstructions, and finally to vitalism with "tonifying" waters against weakening. It would be a subjective and imaginary discourse to compare with a poetic context studied by Bachelard in L'eau et les rêves")[24]​ [Water and dreams]..

The development of medical thermalism in France was the work of the king's doctors. The very lucrative position of general superintendent of the baths, created in 1605, automatically fell to the king's first physician in 1709. According to J. Coste, medical thermalism was a route to social advancement towards nobility, the dream of many doctors under the Ancien Regime. The thermal administration was, therefore, a place of complicity, of links of interests and family strategies, an example of success being that of Théophile de Bordeu.[25]​.

The most famous spas in Central Europe were in the Principality of Liège - with Spa "Spa (Belgium)") notable for its cold waters -, in the Duchy of Nassau - with Schwalbach - for its mineral waters, Wiesbaden for its warm waters or Schlangenbad for its warm waters -, in the free city of Aachen, known for its very hot waters. In Switzerland, they were the resorts of Aargau, with Schintznach and Baden "Baden (Aargau)"), famous for its sulfur waters.

Those stations had open-air public baths, covered private baths, and stoves and steam baths. The waters were drunk directly from the source from dawn. The care provided by the Germans and Swiss was characterized by extensive use of suction cups. Most chronic diseases and the consequences of injuries were treated, with the exception of chest diseases.

During the century, a literary genre about baths (Amusements des eaux) developed in Germany, written in French, the international language of the time. They were above all advice guides, then tourist guides, travel stories, manuals of good manners, mixing gallant anecdotes between curists and erudite controversies about water.[26]​.

Germanic thermalism was thermal tourism for European elites, for nobles and bourgeois, based on the reputation of the waters, the quality of care and the enjoyment of the stay. The entertainment was numerous: walks, picnics, excursions, game rooms (billiards), games of chance (Pharaoh&action=edit&redlink=1 "Pharaoh (game) (not yet written)")), lotteries, dances, concerts and shows... The mundane life of the spa brought together both sexes in a more intimate way than in their usual meeting place, each being able to talk more easily about the other's body and health. According to a text from the time, "it seems that in Aix [Aix-la-Chapelle] being sick or being gallant are the same thing."[27]

This thermal pleasure for wealthy people gave rise to many professions, with beneficial effects on the local and regional economy of the thermal areas. It also attracted thieves and adventurers. According to E. Belmas, this thermalism represented the beginnings of a leisure industry, a luxury trade, and also that of counterfeits, souvenirs and trinkets.[26]​.

The most renowned station in England was Bath, followed by Tunbridge Wells, Buxton "Buxton (Derbyshire)"), Scarborough&action=edit&redlink=1 "Scarborough (Yorkshire du Nord) (not yet drafted)") and Cheltenham. As in Germany, these stations offered leisure and entertainment to aristocrats and gentry, generating important commercial activity. These stations were owned by individuals or private corporations, outside the guardianship of the Crown or the Church. Local businessmen freely exploited the growing taste of the English bourgeoisie for luxury and consumption, eager to buy health and leisure at the same time and in one place.[7]​.

Mineral waters were bottled: those rich in iron were used as purgatives; those of Bath to treat infertility. Doctors patented the waters as medicines, as Nehemiah Grew did for the salts of Epsom waters (rich in magnesium sulfates). This gave rise to a medical literature that was both a scientific study and a commercial prospectus.[7]​.

Portugal has a rich thermal tradition with more than 40 active thermal stations. Caldas da Rainha, founded by Queen Leonor of Viseu in 1485, was the first thermal hospital in the world. Other historical centers include Vidago, Caldas de Monchique") and the Termas de São Pedro do Sul").

Italy, direct heir to Roman tradition, maintains more than 380 thermal establishments. Montecatini Terme, Abano Terme and Salsomaggiore Terme are internationally recognized. The Tuscany region concentrates the largest number of natural thermal springs in Europe.

The waters of the Belle Époque

Thermalism will experience exceptional development in the 20th century, carried by the wave of romanticism in Europe.

For reasons of ease of access, the first thermal resorts were developed earlier in the vicinity or in the interior of large cities. But very soon, the rapid extension of railway links will make isolated stations accessible to Parisians and foreigners.[28] The growth in attendance will take off and will go from 22,000 curists in 1822 to 120,000 in 1855. In Savoy, in Aix-les-Bains, personalities from the political and artistic world, including writers, came to the city to take advantage of the thermal waters and made the city one of the most famous seaside resorts in the world.[5]​ On the borders of Lorraine, half a dozen tourist resorts were being developed such as Plombières-les-Bains, the city of a thousand balconies, Vittel, Contrexéville, Bourbonne-les-Bains, Bains-les-Bains...

In the Pyrenean chain no less than 31 thermal stations will be developed, driven by the imperial taste for water cities. Auvergne was no exception to this movement; Le Mont-Dore"), Royat, La Bourboule, Saint-Nectaire... and above all Vichy, which became the archetype of the thermal village par excellence.

At the beginning of the century, hot springs were defined by their temperature (spring water over 20 degrees), but that norm was changing and any natural mineral water with the appearance of being healing will be called "thermal." The thermal station did not have a medical definition, the term came from common language that designated a stop or pause for public vehicles and then for trains. The law of April 13, 1910 defined a spa as a municipality, fraction or group of municipalities that had mineral springs or an establishment that exploited them. This tautological definition confirms the fait accompli of an already established use. In 1912, the number of these stations was estimated at almost 110 in France.[29]​.

After the Revolution, the Académie nationale de médecine inherited the prerogatives of the Académie royale de médecine, including the supervision of mineral waters. However, their role was limited to recommending that doctors supervise thermal cures. In fact, it was the thermal doctors who ensured the promotion of thermal spas. The century saw the emergence of a medical current that was skeptical or critical of thermalism, which was criticized for the relationships of interest of thermal doctors, the absence of recognized scientific bases, imprecise therapeutic indications and unclear results.

For example, the composition of the waters and their classifications remained uncertain. The first was according to temperature, then those of iatrochemistry and protochemistry (chemistry before Lavoisier). They could be classified according to their dominant chemical element, or as a minor but essential element (copper, arsenic, iron...) or trace element, or even according to their therapeutic use. The link between chemical composition and therapeutic effect remained approximate. The discovery of radioactivity relaunched for a time the study of so-called indeterminate mineral waters (without significant composition), but of consecrated therapeutic use.

To respond to these criticisms, thermal medicine evolved and was rationalized. Until then, thermal resorts were universal treatments and treated many ailments in endless lists. Little by little they specialized, based on more precise therapeutic indications (one or two main indications, and a small number of secondary indications). For example, Vichy for metabolic and digestive diseases, sometimes anemic and kidney diseases; other stations treated osteoarticular, respiratory, dermatological conditions... The stations could stand out and gain their identity, covering the national territory with all pathologies.[29]​ This specialization of stations is specific to France, and does not exist in other countries.[30]​.

Thermalism thus led to debates with multiple facets: scientific, institutional, economic and political. Crenotherapy,[31]​[Note 1]​ made its entry into the university from the 1890s with courses in Toulouse and Bordeaux where the first chairs of medical hydrology were created in these two cities in 1922. In 1939, nine medical faculties already had a chair of hydrology (in addition: Paris, Lyon, Lille, Nancy, Montpellier, Strasbourg and Algiers).[29]​.

According to the imperial decree law of France of January 28, 1860 regulating thermal establishments, the use of the waters did not depend on a medical prescription, and nothing obliged the curist to consult a doctor on the spot. Only medical advice was recommended, the objective was the prosperity of the spa. The cures were thus carried out freely: masseuses, bath staff and hotel staff, in search of tips, played the role of guide-advisors in their progress. The thermal doctors were divided between the need to leave complete freedom to the curists to attract them (curists-tourists) and the desire for greater power (over the curists-patients), or even local political power within the municipality.[32]​.

The political debate was related to the strategy: base the cure on the exclusive use of water (medical thermalism) or also on everything around it (tourist or leisure thermalism). This debate reflected an opposition between the French model (centralized and medicalized) and the German model (decentralized and fun). Firstly, the German model seemed exemplary for its remarkable organization of leisure activities. But after the defeat of 1871, a patriotic reaction highlighted the superiority of French thermalism for its superior quality waters and its most specialized and virtuous spas. But French spas had to be modernized to become more attractive, now past the time when thermal sites received donations during royal or princely visits. Economic imperatives led to approaching the German model with the introduction of taxes on gambling and stays.[34]​.

The legal status of gambling&action=edit&redlink=1 "Casino (place) (not yet drafted)") was confusing: prohibited in 1781, authorized in spas in 1806, authorization repealed in 1836. In reality, there were 150 gambling establishments at the beginning of the 20th century in a situation of "illegal tolerance." Several laws, in 1907, reaffirmed the privilege of seasonal cities (spa and thermal baths) in matters of gambling and gambling taxes. In 1910, a law allowed resorts to charge a tourist tax, although this possibility was hardly applied by city councils, for fear of scaring away clientele.

In 1919, the taxe de séjour (tourist tax) became mandatory and an additional tax was introduced to finance the Office National du Tourisme (founded 1910) and the Institut d'Hydrologie et de Climatologie de Paris (founded 1913). In 1939, of more than a hundred listed spas in France, 75 were officially classified, by law, as 'station hydrominérale" (hydromineral station). The development of French spas at the beginning of the century appears as a desire to surpass Germany and one of the means that France put into practice to emerge as an important tourist country.[34]​.