Ii Modern Medicine

The next advance in the knowledge of the air was made by the English Unitarian divine, Joseph Priestley (1733-1804). He showed that growing green plants would make respired air again respirable, and that they gave off a respirable gas. In 1774 he actually prepared oxygen by heating certain oxides, but was still hampered by the phlogiston theory. The real passage to the modern point of view was made by the French chemist, Lavoisier (1743-94)- By quantitative investigation of the changes during breathing, burning and calcination, he discovered the true com position of respired air, and showed how both carbon dioxide and water are normal products of breathing. The modern physiologi cal study of respiration dates from Lavoisier.

Morbid Anatomy and Clinical Medicine.

During the earlier i8th century there were published several accounts of groups of cases of post-mortem appearances connected with par ticular diseases. Boerhaave regularly attended post-mortem examinations. No general pathological principles were elicited. The theories of disease were still mainly speculative. This gap was bridged by Giovanni Battista Morgagni (1682-1771). He was professor at Padua for 56 years and during this time per formed an enormous number of post-mortem examinations. In his 79th year, there emerged from his vast experience his work On the Seats and Causes of Disease. Its leading feature is the way in which actual cases are recorded. The life history of the patient, the history of his disease, the events in connection with his final illness and manner of death are all recounted with care. The condition of the organs at the post-mortem examination is minutely described and an attempt made to explain the symptoms as the result of the lesions. Morgagni introduced the "anatomical concept" into the study of disease. It is the main element in modern diagnosis.

The work of Morgagni was worthily continued by the Scot, Matthew Baillie (1761-1823), a successful London practitioner, who followed a convenient method in arranging his work by or gans instead of symptoms, as Morgagni had done. The task of naked eye pathological anatomy, effectively begun by Morgagni, was effectively completed by Karl Rokitansky of Vienna (1804 The great teachers of the earlier i8th century, though better equipped as regards knowledge than their predecessors, had hardly any better apparatus for diagnosis than the ancients. The first efficient clinical instrument of precision to merit clinical adoption was the "pulse watch." Sir John Floyer (1649-1734 ), an English provincial physician, introduced in 1707 an instru ment constructed to go for just one minute. Attempts were also made to introduce a thermometer into practice, but the construc tion of suitable instruments proved impossible. Both these ideas

gained final admission to practice during the 19th century.

Two clinical advances of first-class importance, the methods of percussion and auscultation were, however, introduced during the later i8th and early 19th centuries.

Percussion is of great value to the physician as a means of out lining the position of internal organs, especially those of the chest. It was invented (1761) by Leopold Auenbrugger (1722 1809), a Viennese physician. Like the thermometer, it was slow in entering practice.

Even more important than the introduction of percussion was the invention and adaptation of the stethoscope by the Breton physician, R. T. H. Laennec (1781-1826). (See LAENNEc.) Laennec's instrument was first described by him in 1819. It was of the uni-tubular type, and at first a mere roll of paper.

Surgery and Obstetrics.

During the i8th century few new principles were introduced into surgery. Nevertheless the im provements in normal and pathological anatomy had their effects in surgical technique, so that operations could be performed that had seldom before been attempted. Even the greatest surgeon of the century, John Hunter (1728-93) (q.v.) introduced no funda mental new surgical principles. The main clinical improvements of the century, apart from operative technique, were probably those connected with the treatment of syphilis and the treat ment of women in labour.

Syphilis, as has been already indicated, had existed in Europe in the later middle ages, but was then confused with leprosy and other conditions. Its treatment by mercury was practised at least as early as the 15th century, as an inheritance from the Arabian physicians. During the 16th and 17th centuries, various other remedies were tried. In the i8th century the experience of gen erations returned again to mercury.

The second advance was in the treatment and care of women in labour. Scientific obstetric works were produced, especially in France, in the second half of the 17th century. The obstetric for ceps, for long a family secret, became widely known in the 18th century. For long there was great objection by pregnant women to treatment by medical men. The midwives were mostly igno rant, dirty and unskilful, and the resulting loss of life enormous. The objection to the "man midwife" was only gradually over come, but his advent was attended by a great fall in maternal mortality. One of the ablest and most successful of the obstetric physicians was William Hunter (1718-83) (q.v.), the brother of John Hunter. Numerous lying-in hospitals were founded in Eng land and elsewhere in his time.