study of the repair of tendons and his relation to subcutaneous and orthopedic surgery, his influence on the treatment of hernia, his observations on the inflammation of veins, the clotting of blood, and the communicability of puerperal fever. Hunter discovered the distribution of the olfactory nerves, explained the placental circulation, traced the course of the tubuli uriniferi, advanced our knowledge of the lymphatic system, distinguished Hunterian chancre from chancroid ulcer, invented double bellows for the resuscitation of the apparently drowned and advocated the use of oxygen in the treatment of such cases. He experimented in artificial feeding, made a special study of intussusception, threw light on the nature of alcoholic fermentation, recorded a case of post-mortem digestion of the tissues of the stomach, observed hydatids in the liver of the mongoose, and investigated the motion and the temperature of plants.

Hunter was interested in the mental processes and their development as a part of an interrelated system of natural phenomena. He studied colorblindness ten years before John Dalton, was interested in the accommodation of the eyes, discovered what was later called the specific energy of the nerves, traced the growth of the perception of space, noted the abundance of human instincts, anticipated modern psychology in reference to types of

memory and imagination and the physiological phases of the emotions, studied the expression of the emotions in the lower animals, recognized the survival value of anger and fear, and wrote in an enlightened way concerning what is now called the sublimation of the emotions.

REFERENCES

Baron, J.: Life of Jenner. 2 vols., London, 1827-38.

Gross, Samuel David: John Hunter and his Pupils. Philadelphia, 1881.

Hunter, John: (1) Essays and Observations on Natural History, Anatomy, Physiology, Psychology, and Geology, being his Posthumous Papers, etc. Edited by Richard Owen. 2 vols., London, 1861.

(2) Observations on Certain Parts of the Animal Economy. London, 1792.

(3) Works. Edited by J. F. Palmer. London, 1837. Ottley, Drewry: The Life of John Hanter. Philadelphia, 1839. Paget, Stephen: John Hunter, Man of Science and Surgeon. London, 1897.

Stirling, William: Some Apostles of Physiology. 1902.

Keith, Sir Arthur: Menders of the Maimed.

Guerini, Vincenzo: A History of Dentistry. Philadelphia and New York, 1909, pp. 316, 318, 324.

CHAPTER IX

MORBID ANATOMY, AND HISTOLOGY:
MORGAGNI, BICHAT

WITHINGTON in his "Medical History" says that local pathology, the study of the tissues, and local diagnosis form the three legs of the tripod upon which the genius of modern medicine took her seat. The early history of these three-morbid anatomy, histology (iσrós, tissue), and one aspect of local diagnosis - will occupy our attention in this and in the following chapter.

Giovanni Battista Morgagni (1682-1771) has been called the Father of Pathology. His book "Concerning the Seats and Causes of Diseases investigated by Anatomy" ("De sedibus et causis morborum per anatomen indagatis," 1761) gave the results of postmortems known to himself, to his master Valsalva, and to others among their predecessors, such as Bonetus. Morgagni's study of the abnormal was based on a sound knowledge of the normal. He considered the commonest diseases the worthiest objects of investigation, and he was careful to establish the relations between the records of his autopsies and the symptoms of the precedent diseases. His aim was to explain disease by refer

ence to its seat or location rather than to produce a systematic work on morbid anatomy. After his time it became more and more the practice to inquire "Where is the disease?" The old humoral pathology, which had continued to play a large part in the time of Sydenham and in that of Boerhaave, was at last superseded by something better.

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Morgagni was particularly definite concerning the location and causes of apoplexy, to which disease his colleague Ramazzini — one of the earliest writers on the pathology of the occupations well as Valsalva, and Valsalva's master, Malpighi, had fallen victims. The cases recorded in Morgagni's volumes show that he had observed the suffusion of blood on the surface of the hemispheres (in some cases with rupture of the arteries at the basis of the brain), intraventricular hæmorrhage with laceration of the choroid plexus, and the extravasation of blood between the pia and the dura mater as well as into the substance of the cerebrum. Morgagni noted that the cerebellum is less frequently the seat of apoplexy than is the cerebrum. He confirmed the observation of Valsalva - and of some of the leading authorities of antiquity that if the left parts of the body are paralyzed the injury is to be found on the right side of the brain; and if the right, on the left. Morgagni records, likewise, a case in which a fracture of the left temple was fol

lowed by speechlessness and loss of control of the right hand. Commenting on a case of apoplexy accompanied by a fall, he remarks, "Nor do I attribute it to the accidental fall, but the fall to it."

In several of his cases of apoplexy Morgagni mentioned the excessive use of wine, but among the causes of the disease he was inclined to lay special emphasis on aneurism. Nothing is more natural, he writes, than to call to mind the rupture of aneurisms in the abdomen and thorax, and even to imagine that something similar to this might sometimes occur within the cavity of the cranium; especially as those symptoms often precede the most dangerous apoplexies which would of themselves lead us to imagine such a circumstance. For instance, two aneurisms preceded that apoplexy which in twelve hours carried off the learned and worthy Ramazzini. In fact, Morgagni records the observation, in another case, of those miliary aneurisms, the rupture of which is to-day recognized as the commonest cause of cerebral hæmorrhage. It might be added incidentally that, according to Morgagni, Valsalva and others had known cases in which the circulation in a limb had been adequately restored by collateral arteries after the chief artery had become obliterated following an operation for aneurism.

As Osler notes, Morgagni recognized that the infection with which aneurism is especially con