Marie Francois Xavier Bichat, a French anatomist and physiologist, born at Thoirette-en-Bresse, department of the Am, Nov. 11, 1771, died in Paris, July 22,1802. He was a student of the Jesuit seminary of St. Irenee at Lyons until the revolution in 1789, when he returned home and began the study of anatomy under his father, a physician at Poncin, and afterward attended lectures at the hospital of Lyons. Driven from Lyons again by the revolution, he went in 1793 to Paris to study surgery under Desault at the H6tel Dieu, who, pleased with his zeal and ability, invited him to reside in his own house, subsequently adopted him as his son, and destined him to be his successor. After the death of Desault (1795) Bichat arranged and published the works of his master, and opened a school of anatomy, physiology, and surgery. He also undertook a series of experiments on the chemical, physical, physiological, and vital properties of the different tissues of the animal economy. During a severe attack of illness, caused by overwork, he passed the time in maturing his views of anatomy and physiology, and sketched the plan of the works in which these views were afterward developed. As soon as he had partially recovered, he recommenced his labors.

In spite of increasing weakness, he continued to pass several hours a day in a damp cellar, macerating animal tissues and making various experiments to ascertain the properties of each particular kind of structure in the organs of the body. In a short time he was seized with typhoid fever, which proved fatal in the course of 14 days. Although he had lived less than 31 years, he had done enough already to immortalize his name. He was the first who undertook a systematic analysis to reduce the complex structures of the body to their elementary tissues, and to ascertain the peculiar properties, chemical, physical, and vital, which characterize each simple tissue. The idea of such a work had been suggested by partial analyses before, but his Anatomie generate formed a new era in the development of that branch of science. The work abounds with minute and laborious research, extensive and elaborate experiment, conducted with intuitive insight and practical skill; and though a monument of fame, it was completed and published in a year. It was recognized at once and universally as the work of a great genius. Soon after its publication he commenced his Anatomie descriptive, conceived on a new plan; this was left unfinished, but was completed according to his directions by his friends and disciples.

There was little systematic order in the study of anatomy and physiology before this time. Dissections were made chiefly with a view to the practical art of surgery alone, and not with any comprehensive view of general analysis. He first laid stress on the general distinction between conscious and unconscious life in the body, and the correspondingly incessant action of one set of organs, sleeping or waking, contrasted with the interrupted action of another set of organs, which are active in the waking state and passive during sleep. He divided the organism, therefore, into two distinct mechanisms which he called the organic and relational, or the vegetative and the animal. These distinctions are admitted at the present day, although the vegetative or the organic mechanism is more commonly subdivided into the nutritive and the reproductive systems. He fell into some errors by generalizing too extensively, without a sufficient knowledge of minor facts, and these errors have deterred his followers from pursuing the same course. His Recherches sur la me et la mort contains the germs of a revolution in the study of anatomy and physiology, but its defective definitions and manifest errors have caused them to be overlooked.

The same idea runs through all his works, and that is the distinction between conscious and unconscious bodily life and motion.