TABES DORSALIS WITH UNILATERAL ANÆSTHESIA : A CONTRIBUTION TO THE PATHOGENESIS OF THE DISEASE
to Professor Schafer, that we owe our most accurate a] knowledge of the absorption of water by the lungs in the c( act of drowning. He found that the amount taken into the oj lungs of dogs varied greatly. The sixth dog of his experi-1 mental series took 780 cubic centimetres of water into its ir lungs during an immersion of five minutes and re-T covered spontaneously. He found that the air expired g; in the act of drowning was equal to only a fraction n of the water taken into the lungs. A
... o the lungs. A specimen from p the collection in the Museum of the Royal College of o: Surgeons of England of the lungs of a cat drowned a in water containing plaster-of-Paris shows that the aire passages from the trachea to the terminal bronchioles are filled with plaster ; near the roots and along the dorsal parts the plaster has even reached the infundibula and air cells. The lungs of drowned persons are large and do not *] collapse : (1) because their capillaries are overladen with blood ; (2) because the air passages and spaces of the dorsal and deeper parts of the lung are filled with water; and (3) I because the anterior (ventral) and diaphragmatic parts of the lung are distended with air. The appearance of the lungs gave rise to the ancient belief that the drowned and I hanged died in the act of inspiration. The parts of the lungs which become emphysematous in the act of drowning A are those which are most liable to this condition in common respiratory diseases. I do not propose to discuss now the cause of emphysema, but those interested will find this condition very thoroughly analysed by N. Ph. Tendeloo.14 The capillary system of the lung is often seriously damaged. s How often the froth that exudes from the respiratory & e g r a v e ; passage is blood-stained I cannot discover ; in the recordsr often very brief-of the Royal Humane Society it is occat sionally noted. I had an opportunity of examining the lungs E of the walrus which was accidentally drowned in the Zoo-( logical Gardens during the present winter. Mr. William I Pearson, prosector of the College, poured a solution of plaster-E of-Paris into the trachea ; we were surprised to note that in i several of the deeper parts of the lungs it had also passed i into the smaller veins ; we were able to trace these veins to 1 infundibula full of plaster-of-Paris. On microscopic exa-( mination large areas o the lungs were found to be full of 1 blood from rupture of the smaller vessels. At these points < of rupture the plaster entered the vessels. I infer that air i would also have entered into the veins if artificial resuscitation had been applied. Is it not possible-nay, probablethat some of the cases which died suddenly after being partially restored are killed by air embolism ? Out of six cases of asphyxia in young children Dr. Ivy McKenzie 15 found large pulmonary extravasation of blood in one, and minute extravasations in four. Whichever form of resuscitation be adopted it is important that the condition of the lung be kept in mind. INFLATION OF THE LUNGS CONTRASTED WITH NATURAL BREATHING. Inflation of the lung does not produce a pulmonary movement similar to that which takes place either in a natural inspiration or in an inspiration produced by an artificial expansion of the chest. When air is blown into the lungs those parts expand-as J. Hutchinson 16 demonstrated in 1852-which are situated against the most yielding parts of the thoracic cavity. The most yielding wall is (1) the diaphragmatic and (2) the anterior sterno-chondral wall. Hence when the lungs are inflated the chief movement seen is one at the epigastrium. The water-logged parts of the lungs lying against the rigid apical and dorsal walls are expanded to a much less extent. The resistance offered by the thoracic wall to the expansion of the lungs was found by Hutchinson to be very considerable. In two men, just dead, he found that a pressure of 30 millimetres of mercury was necessary to introduce 1000 cubic centimetres (twice the amount necessary for resuscitation), whereas when he removed the lung from the thorax he could introduce 1500 cubic centimetres at a pressure of 10 millimetres of mercury. In one case in which he inflated the lungs while in situ he found that they ruptured 14 Studien ueber die Ursachen der Lungen-Krankheiten, Wiesbaden 1902, pp. 470. hen 1430 cubic centimetres had been introduced at a ressure of 3j'5 millimetres of mercury. Inflation differs so from natural inspiiation in its action on the blood-Ontent of the lung; whereas inflation diminishes the amount E blood and lymph in the lung by forcing on the blood and mph along their courses natural inspiration serves to icrease the volume of blood and lymph within the lung. he expiratory movement caused by compressing the epiastrium and anterior wall of the sternum does not differ laterially from the effect of a natural expiration. Comression applied to the anterior wall of the chest acts chiefly n the anterior part of the lung-the dorsal and apical parts re but slightly affected. The pressure applied serves to mpty the lung of air and blood.