LEEUWENHOEK. 69 



he find that was new? "The House I Live In" gives 

 an account of the voyage which a drop of blood makes 

 when it leaves the heart, passes through J;he arteries 

 to the muscles and bones, and returns to the heart 

 through the veins. 



The credit of discovering this trip of the drop of 

 blood is due to an English physician, William Harvey, 

 who died when Anthony was twenty-five years old. 



But there was one part of the journey of the blood 

 which Dr. Harvey did not explain. 

 When the red traveler reaches its 

 destination, how does it leave the 

 artery, get through the muscles, 

 and jump into the veins ? 



This question Anthony answered 

 by the use of his microscope. He 

 found the minute capillary (or 

 hair) tubes which convey the blood 

 from the arteries to every part of 

 the muscles and bones, and throw 

 it into the veins, so that it may 

 go back to the heart and lungs. 

 About the time of this discovery, 



Improved Microscope. 



Anthony received a visit from 

 Peter the Great of Russia, who was delighted to see, 

 through the microscope, the circulation of the blood in 

 the tail of an eel. 



He discovered that the human hair is solid and not 

 a tube ; that cochineal, which produces red and purple 

 dyes, is an insect and not a seed as people supposed ; 

 that the grubs, or maggots, which appear upon spoiled 

 meat are hatched from eggs, and are not sponta- 



