BLONDIN 



775 



BLOOD 



BLONDIN, PIERRE EDOUARD (1874- ), a 

 Canadian legislator and political leader, mem- 

 ber of the House of Commons since 1908, and 

 since 1914 a member of the Conservative Min- 

 istry headed by Sir Robert L. Borden. Blondin 

 was born at Saint Frangois du Lac, Que., and 

 attended Nicolet College and Laval University. 

 After holding several local offices he entered 

 Parliament in 1908. In 1914 he was appointed 

 Minister of Inland Revenue, a position which 

 he exchanged in the next year for that of Sec- 

 retary of State and Minister of Mines. 



BLOOD. Nature has provided for the dis- 

 tribution of dissolved food materials through- 

 out the human body by a wonderful system of 

 tubes, called arteries and veins, through which 

 circulates a life-giving substance we call blood. 

 This collection of tubes may be compared to 

 the water-works system of a great city, by which 

 the water is pumped into pipe-lines and carried 

 to the different homes, office buildings and 

 factories. 



Composition. Blood itself is a liquid like 

 /water, for it consists of a substance called 

 plasma, which is about nine-tenths water. In 

 this are floating millions of minute bodies 

 called corpuscles. Blood also contains another 

 substance, a ferment which causes it to clot 

 when drawn from the body or exposed to the 

 air at the surface of a wound (see subhead 

 Clotting, below). 



Corpuscles. There are two kinds of blood 

 corpuscles, red and white, and because the 

 former are by far the more numerous, they give 

 the blood its color. In a drop of blood the 

 size of a pinhead there are about 5,000,000 red 

 corpuscles and 6,000 white ones. The red are 

 shaped like a coin, except that they are thinner 



RED CORPUSCLES 

 Magnified about one thousand diameters. 



in the center than at the edges, and they are 

 only %2oo of an inch in diameter. In them is 

 an important substance containing iron, which 

 absorbs oxygen from the air in the lungs and 

 carries it to the tissues of the body. This sub- 



a 



stance is bright red when charged with oxygen, 

 but turns to a dark red or purple when the oxy- 

 gen has been given off. It is called hemoglobin. 



The white corpuscles, though fewer in num- 

 ber than the red, are a little larger. They are 

 shaped like tiny balls and one of their func- 

 tions is to protect the body against certain dis- 

 eases. To illustrate: If a wound is made in 

 such a manner that bacteria are left on the 

 torn surfaces, the white corpuscles rapidly mul- 

 tiply on these surfaces and tend to destroy the 

 bacteria. This they do by absorbing them and 

 carrying them out of the system, or destroying 

 them. 



Clotting. When blood is drawn from the 

 body or exposed to the air on the surface of a 

 wound, minute threads soon extend through it 

 in all directions, and 

 these hold the corpuscles 

 in their meshes, forming 

 a solid mass, or clot. 

 The clotting is caused 

 by fibrinogen, which 

 manufactures the 

 threads. It seems to be 

 a wise provision of WRITE CORPUS- 

 nature to stop the flow CLES 



of blood from a wound. Showing movements, 

 A i , -n f similar to those of the 



A clot will form more amoeba (which see). 



quickly over a wound <> B e f il ?" i l lg of 



movement ; ( b ) forma- 



with rough, ragged tion of foot-like pro- 



edges. Clean sand *& ^mTu) 

 placed on a wound as- dead corpuscle. 

 sists in the formation of clot, and may be the 

 means of saving life. 



Quantity of Blood. The quantity of blood 

 in the body is about one-thirteenth the weight 

 of the body. A man of average weight has 

 from twelve to fifteen pounds of blood; allow- 

 ing a pint to the pound, this amounts to about 

 six quarts. As the normal quantity in any 

 human body is almost perfectly proportioned 

 to its needs, the loss of only a little through 

 bleeding or disease induces weakness and dizzi- 

 ness. If not replaced by natural processes 

 serious results may follow (see ANAEMIA). 



Functions. One of the chief functions or 

 uses of the blood is to carry the nutriment re- 

 ceived from food to all parts of the body. t 

 Those portions of food absorbed through the 

 membrane of the intestines are conveyed by 

 the thoracic duct to the large vein. Those por- 

 tions that are absorbed through the liver are 

 conveyed directly from that organ into the 

 blood current. The function of carrying oxygen 

 to all parts of the body has been explained 



