112 SEVENTEENTH CENTURY. PT. ill. 



Bartholomew's Hospital. Here he taught his theory in his 

 Lectures of 1619, and at last published a small book on the 

 circulation of the blood in 1628. Yet none of the older 

 physicians would believe he was right, and Harvey told a 

 friend that he lost many patients in consequence of his new 

 doctrine. It is greatly to the credit of the unfortunate King 

 Charles L, who was reigning at this time, and whose private 

 physician Harvey was, that he gave him many opportunities 

 of making physiological experiments on the animals in the 

 royal parks, and took great interest in his discoveries. 

 Harvey wrote several other valuable books, and traced the 

 development of the chicken in the egg. He was of a very 

 gentle and modest disposition, and disliked controversy so 

 much that he could scarcely be persuaded to publish his 

 later investigations when he found what disputes were occa- 

 sioned by his great discovery of the circulation of the blood. 

 He died in 1657, in his eightieth year. 



Discovery of the Vessels which carry Nourish- 

 ment to the Blood, 1622-1649. Harvey's doctrine of 

 the circulation of the blood was the real starting-point of 

 physiology, or the science of living bodies, and when the true 

 action of the arteries and veins was known, many other 

 vessels of the body were soon better understood. The 

 most important of these were the vessels which carry nourish- 

 ment from all parts of the body to make fresh blood. In 

 1622 Gaspard Asellius, Professor of Anatomy at Pavia, saw 

 a white fluid flowing from some thread-like tubes in the 

 body of a dog which he was dissecting. This dog had been 

 eating food just before he died, and Asellius found that the 

 fluid came from the intestines and was the nourishing matter 

 of the food He called these fine tubes lacteals, because 

 the fluid in them looked like milk. Some years later, in 

 1647, Jean Pecquet, an anatomist of Dieppe, discovered 



