140 THE STOCK OWNER S ADVISER. 



A similar escape takes place, but to a less extent from the capil- 

 laries. In some inflammation the escape of red corpuscles even 

 exceeds the white. It is certain that all new cells found in 

 inflamed tissues, as a direct result of the injury which caused 

 the process, are escaped blood corpuscles. The tissues of an in- 

 flamed part are softer than natural, watery or solid looking, and 

 in either case the component tissues are blurred or altogether in- 

 distinguishable. 



Having thus briefly described the succession of changes which 

 occur in the process of inflammation, we will next consider how 

 an injury can produce them. It has been lield that injury causes 

 abnormal conditions of the blood, of the tissues, of the nerves, 

 and of the blood vessels. On one or other or all of these parts 

 it necessarily must act. The essential lesion of inflammation is 

 a change in the vessel wall, resulting from an injury, which in- 

 creases the friction naturally offered to the passage of the blood, 

 and IS a step towards death. To cover all that we know of the 

 escape of fluid and corpuscles, it is necessary to assume that the 

 molecular change not only increases the friction between the 

 blood and the vessel wall, but also that it renders the latter more 

 porous. The signs of inflammation are redness, heat, swelling, 

 pain, and impaired function. Redness and heat may be taken 

 together as depending upon the quantity of blood passing 

 through the part in a unit of time. Swelling is caused by exu- 

 dation of fluid and corpuscles. Pain is due to pressure of the 

 effusion on nerve endings, perhaps also to chemical violation of 

 them. Impaired function is due to the fact that every tissue is 

 injured by inflammation. 



The following A^arieties of inflammation are to be regarded as 

 steps in the process of inflammation due to variation in the re- 

 sisting power of the tissue, the intensity of the cause, and the 

 duration of its action: 



Serous Ixflammatiox. — As a result of slight injury, the nor- 

 mal transudation from the vessels is increased in quantity and 

 contains excess of albumen, but very few leucocytes. The best 



