Circulation of blood established. 35. The Harveian theory gained ground, though obstinate prejudice gave way but slowly. It was confirmed by the experiment of transfusing blood, tried on dogs, at the instance of Sir Christopher Wren, in 1657, and repeated by Lower in 1661.[1118] Malpighi in 1661, and Leeuwenhoek in 1690, by means of their microscopes, demonstrated the circulation of the blood in the smaller vessels, and rendered visible the anastomoses of the arteries and veins, upon which the theory depended.[1119] From this time it seems to have been out of doubt. Pecquet’s discovery of the thoracic duct, or rather of its uses, as a reservoir of the chyle from which the blood is elaborated, for the canal itself had been known to Eustachius, stands next to that of Harvey, which would have thrown less light on physiology without it, and like his, was perseveringly opposed.[1120]
[1118] Sprengel, Hist. de la Médecine, vol. iv., p. 120.
[1119] Id. p. 126, 142.
[1120] Portal. Sprengel.
Willis-Vieussens. 36. Willis, a physician at Oxford, is called by Portal, who thinks all mankind inferior to anatomists, one of the greatest geniuses that ever lived; his bold systems have given him a distinguished place among physiologers.[1121] His Anatomy of the Brain, in which, however, as in his other works, he was much assisted by an intimate friend, and anatomist of the first character, Lower, is, according to the same writer, a masterpiece of imagination and labour. He made many discoveries in the structure of the brain, and has traced the nerves from it far better than his predecessors, who had in general very obscure ideas of their course. Sprengel says that Willis is the first who has assigned a peculiar mental function to each of the different parts of the brain; forgetting, as it seems, that this hypothesis, the basis of modern phrenology, had been generally received, as I understand his own account, in the sixteenth century.[1122] Vieussens of Montpelier carried on the discoveries in the anatomy of the nerves, in his Neurographia Universalis, 1684; tracing those arising from the spinal marrow which Willis had not done, and following the minute ramifications of those that are spread over the skin.[1123]
[1121] P. 88. Biogr. Univ.
[1122] Sprengel, p. 250. See vol. iii., p. 204.
[1123] Portal, vol. iv., p. 5. Sprengel, p. 256, Biogr. Univ.
Malpighi. 37. Malpighi was the first who employed good microscopes in anatomy, and thus revealed the secrets, we may say, of an invisible world, which Leeuwenhoek afterwards, probably using still better instruments, explored with surprising success. |Other anatomists.| To Malpighi anatomists owe their knowledge of the structure of the lungs.[1124] Graaf has overthrown many errors, and suggested many truths in the economy of generation.[1125] Malpighi prosecuted this inquiry with his microscope, and first traced the progress of the egg during incubation. But the theory of evolution, as it is called, proposed by Harvey, and supported by Malpighi, received a shock by Leeuwenhoek’s or Hartsoeker’s discovery of spermatic animalcules, which apparently opened a new view of reproduction. The hypothesis they suggested became very prevalent for the rest of the seventeenth century, though it is said to have been shaken early in the next.[1126] Borelli applied mathematical principles to muscular movements in his treatise De Motu Animalium. Though he is a better mathematician than anatomist, he produces many interesting facts, the mechanical laws are rightly applied, and his method is clear and consequent.[1127] Duverney, in his Treatise on Hearing, in 1683, his only work, obtained a considerable reputation; it threw light on many parts of a delicate organ, which, by their minuteness, had long baffled the anatomist.[1128] In Mayow’s Treatise on Respiration, published in London, 1668, we find the necessity of oxygen to that function laid down; but this portion of the atmosphere had been discovered by Bathurst and Henshaw in 1654, and Hooke had shown by experiment that animals die when the air is deprived of it.[1129] Ruysch, a Dutch physician, perfected the art of injecting anatomical preparations, hardly known before, and thus conferred an inestimable benefit on the science. He possessed a celebrated cabinet of natural history.[1130]
[1124] Portal, iii., 120. Sprengel, p. 578.