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which the lungs were also always kept very full and without any motion, there being a 

 continued blast of air forced into the lungs by the first pair of bellows, supplying it as 

 fast as it could find its way quite through the coat of the lungs, by the small holes 

 pricked in it, as was said before. This being continued for a little while, the dog, as I 

 expected, lay still, as before, his eyes being all the time very quick, and his heart beating 

 very regularly. But upon ceasing this blast, and suffering the lungs to fall and lie still, 

 the dog would immediately fall into dying convulsive fits, but be as soon revived again 

 by the renewing the fulness of his lungs, with the constant blast of fresh air. 



" Towards the latter end of this experiment a piece of the lungs was cut quite off, 

 where 'twas observable that the blood did freely circulate, and pass through the lungs, 

 not only when the lungs were kept thus constantly extended, but also when they were 

 suffered to subside and lie still ; which seem to be arguments, that as the bare motion 

 of the lungs without fresh air contributes nothing to the life of the animal, he being 

 found to survive as well when they were not moved as when they were ; so it was not 

 the subsiding or movelessness of the lungs that was the immediate cause of death, or the 

 stopping the circulation of the blood through the lungs, but the want of a sufficient 

 supply of fresh air." 



It was thus evident that an animal could be kept alive when all 

 respiratory movements of the chest wall had ceased, and, secondly, 

 even when the lung was kept inflated with fresh air, life was main- 

 tained. Respiration, therefore, depended not on movements of the 

 lungs, but on a supply of fresh air. 



RICHARD LOWER. 



1631-1691. 



THE name of Lower — a Cornishman — is still preserved in 

 anatomical literature by the name " tubercle of Lower." He 

 did a large amount of work for Thomas Willis while the latter 

 resided in Oxford. At the death of Willis, in 1675, he came to 

 London. His TracAatus de Corde, item de Motu et Colore Sanguinis was 

 published in 1669, and an edition of his Bromographia — I only know 

 it in German — in 1715. The difference between the colour of venous 

 and arterial blood was well known, the difference in colour being 

 ascribed to a kind of combustion taking place in the heart. It will be 

 noticed that the work of Lower deals not only with the heart, but with 

 the motion and colour of the blood. Lower saw the greater bright- 

 ness, i.e. redness, in the upper part of a blood clot or crassamentum, 

 and attributed it to its proper cause, the action of the air (De Corde, 

 c. hi., p. 178). He also saw that a black crassamentum becomes bright 

 red when it is turned up and exposed to the air. Lower suspected 

 that, as the blood passes through the lungs, the change in colour is 

 effected. This he put to the test by using the experiment of Hooke, 



