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Pergunta: Quando foram descobertos os poros da pele?
Question: When were skin pores discovered?
Although pores couldn't be seen, they were speculated about anciently.
Contrary to the critics' assertion, the medicine of antiquity had long speculated and written about "pores."
- Empedocles, a Greek philosopher who lived from about 490–430 B.C., believed that air and vapour could pass into or out of the body via pores. 
- Galen, the Greek physician of the Roman era (A.D. 129–c. 210) likewise believed that "innnumerable skin pores" drew air into the body, and also expelled wastes.  Galen was of multiple opinions on sweat (Gk ιδρος=hidros), but he sometimes claimed that it leaked out from skin pores in droplet form. 
- A variety of other classical physicians (such as Ascelepiades, Petronas, Soranus, Themison) believed that tightening of the pores was a potential cause of disease, and a variety of regimens were recommended to overcome this (e.g. purging, hot baths and drinks, heavy bedclothes to cause sweats, induced vomiting). 
- John of Gaddesdon (c.1280–1349?1361) was physician to the Royal Household in England during the 14th century, and the first English author of a published medical book.  He wrote of a disease that:
- The cause of it is in the grossness of the matter of the body or the blocking up of the pores from an external cause ... the heat of the sun or a fire, or from cold water; briefly anything that closes the pores and prevents the escape of vapours. 
- French physician Ambroise Paré (1510–1590) wrote in 1554 that the skin "is penetrated by many pores or breathing places, as we may see by the flowing out of sweat." 
Despite at least two millenia of theory and discussion in the medicine of antiquity, the skin's pores had not been seen! English anatomist William Cumberland Cruikshank (1745-1800) indicated that "after some pains, and assisted with a pretty good microscope, I have not been able to discover perforations in the cuticle or rete mucosum [i.e. pores in the skin].... I believe, nevertheless, that they certainly exist." 
- E.T. Renbourn, "The Natural History of Insensible Transpiration: A Forgotten Doctrine of Health and Disease," Medical History 4/2 (April 1960): 135. off-site
- Renbourn, 135–136.
- Renbourn, 136.
- Renbourn, 136–137.
- "John of Gaddesden's Rosa Anglica," King's College London off-site
- John of Gaddesden, Rosa Anglica practica medicine a capita ad pedes (Pavia: Joanes-Antonius Birreta, 1492); translation and cited by Renbourn, 137.
- Ambrose Paré, Works (1554); Trans. from Latine by J. Johnston, 1664; cited by Renbourn, 137.
- W.C. Cruikshank, Experiments on the Insensible Perspiration of Huamn Bodies, etc. (1785); cited by Renbourn, 146.