Xavier Bichat

Marie François Xavier Bichat (/biːˈʃɑː/; French: [biʃa]; 14 November 1771 – 22 July 1802) was a French anatomist and pathologist, known as the father of modern histology. Although he worked without a microscope, Bichat distinguished 21 types of elementary tissues from which the organs of the human body are composed. He was also "the first to propose that tissue is a central element in human anatomy, and he considered organs as collections of often disparate tissues, rather than as entities in themselves". The buccal fat pad (also called Bichat’s fat pad) was named after him.

Although Bichat was "hardly known outside the French medical world" at the time of his early death, forty years later "his system of histology and pathological anatomy had taken both the French and English medical worlds by storm." The Bichatian tissue theory was "largely instrumental in the rise to prominence of hospital doctors" as opposed to empiric therapy, as "diseases were now defined in terms of specific lesions in various tissues, and this lent itself to a classification and a list of diagnoses".

Bichat was born in Thoirette, Franche-Comté. His father was Jean-Baptiste Bichat, a physician who had trained in Montpellier and was Bichat's first instructor. His mother was Jeanne-Rose Bichat, his father's wife and cousin. He was the eldest of four children. He entered the college of Nantua, and later studied at Lyon. He made rapid progress in mathematics and the physical sciences, but ultimately devoted himself to the study of anatomy and surgery under the guidance of Marc-Antoine Petit (1766–1811), chief surgeon at the Hôtel-Dieu of Lyon.

At the beginning of September 1793, Bichat was designated to serve as a surgeon with the Army of the Alps in the service of the surgeon Buget at the hospital of Bourg. He went home in March 1794, then moved to Paris, where he became a pupil of Pierre-Joseph Desault at the Hôtel-Dieu, "who was so strongly impressed with his genius that he took him into his house and treated him as his adopted son." He took active part in Desault's work, at the same time pursuing his own research in anatomy and physiology.

The sudden death of Desault in 1795 was a severe blow to Bichat. His first task was to discharge the obligations he owed his benefactor by contributing to the support of his widow and her son and by completing the fourth volume of Desault's Journal de Chirurgie, which was published the following year. In 1796, he and several other colleagues also formally founded the Société Médicale d'Émulation, which provided an intellectual platform for debating problems in medicine.

In 1797, Bichat began a course of anatomical demonstrations, and his success encouraged him to extend the plan of his lectures, and boldly to announce a course of operative surgery. At the same time, he was working to reunite and digest in one body the surgical doctrines which Desault had published in various periodical works; of these he composed Œuvres chirurgicales de Desault, ou tableau de sa doctrine, et de sa pratique dans le traitement des maladies externes (1798–1799), a work in which, although he professes only to set forth the ideas of another, he develops them "with the clearness of one who is a master of the subject."

In 1798, he gave in addition a separate course of physiology. A dangerous attack of haemoptysis interrupted his labors for a time; but the danger was no sooner past than he plunged into new engagements with the same ardour as before. Bichat's next book, Traité des membranes (Treatise on Membranes), included his doctrine of tissue pathology with a distinction of 21 different tissues. As worded by A. S. Weber,

As soon as it appeared (January and February of 1800), it was regarded as a basic and classic text. It was cited in a host of other works, and almost all thinking men placed it with honor in their libraries.