CHAPTER I 

 THE BLOOD 



Importance of the blood Quantity of blood Opacity Taste Reaction Specific grav- 

 ity Temperature Color Laking of blood Blood-corpuscles Red corpuscles 

 Hemoglobin Precipitin-test for blood Development of red corpuscles Leucocytes 

 Lymphocytes Blood-platelets Plasma and serum Fibrinogen Serum-globulin 

 Serum-albumin Extractives and salts Coagulation of the blood Prothrombin and 

 thrombin Uses of coagulation. 



Importance of the Blood. With the progress of knowledge and the 

 accumulation of facts in physiology, the importance of the blood in its 

 relation to the processes of animal life becomes more and more thor- 

 oughly understood and appreciated. The blood is the most abundant 

 and highly organized of the liquids of the body, providing materials for 

 the re-formation of all parts, without exception, receiving the products 

 of their katabolism and conveying them to the proper organs by which 

 they are removed from the system. These processes require, on the 

 one hand, constant renewal of nutritive constituents, and, on the other, 

 constant purification by the prompt removal of effete matters. Those 

 tissues in which the processes of nutrition are active are supplied with 

 blood by means of vessels ; but some, less highly organized, like the 

 epidermis, hair, cartilage, etc., which are called extravascular because 

 they are not penetrated by vessels, are none the less dependent on the 

 blood, as they imbibe nutritive matters from the blood of adjacent 

 parts. 



The importance of the blood in the processes of animal life is evi- 

 dent ; and in animals in which nutrition is active, death is the immediate 

 result of its abstraction in large quantity. Its importance to life in this 

 regard can readily be demonstrated by experiments on the inferior ani- 

 mals. If, in a small dog, a canula is adapted to a syringe introduced 

 through the right jugular vein into the right side of the heart, and a great 

 part of the blood is suddenly withdrawn, immediate suspension of all the 

 so-called vital processes is the result ; and if the blood is afterward 

 returned to the system, the animal is as suddenly revived. 



Certain conditions, one of which is diminution of the heart's action 

 after copious hemorrhage, prevent the escape of all the blood from the 

 body, even after division of the largest arteries ; but after the arrest of 



