CONGESTION, ACTIVE AND PASSIVE. 439 



bloocl filling the arteries and capillaries, and the dusky hue of 

 the finger-tip to dark venous blood filling the capillaries and 

 veins. But not only is there a difference in the vessels which 

 are distended in these two kinds of congestion, there is also a 

 difference in the current through them. In arterial congestion 

 the blood is streaming rapidly through the vessels, bringing a 

 constant supply of fresh oxygen and fresh nutriment to the 

 tissues, and removing the waste products as rapidly as they are 

 formed, so that the part in which arterial congestion is present 

 is in the best possible conditions for health and growth, and 

 for repair if it sliould happen to be injured. This arterial 

 congestion is usually distinguished by the term active conges- 

 tion. In venous congestion there is no doubt more blood than 

 usual in the part, but it is of no service to it, for it is stagnant. 

 Instead of bringing fresh supplies of oxygen and nutriment, it 

 remains in the vessels until its oxygen is entirely consumed, 

 and its colour becomes almost black; the products of waste 

 accumulate in it, and interfere with the nutrition of the tissues, 

 as the ashes in a grate choke the fire. Nor is its injurious 

 action negative only, it is positive as well ; for while it does no 

 good itself, it keeps the vessels filled, and prevents any new 

 blood from entering them. This is venous, or, as it is often 

 termed, passive congestion. Judging by the pictures I have 

 just drawn of the two sorts of congestion, one would say tlierf* 

 could be no doubt whic^Ji was the better, and yet one would look 

 more alarmed at the news that some organ w^as in a state of 

 active congestion than if one were informed that the congestion 

 was passive. The reason of this is, that active congestion is 

 frequently regarded as almost synonymous with inflammation, 

 w^hereas the two are widely different. Congestion may, and 

 very frequently does, exist without inflammation, and inflam- 

 mation sometimes exists without congestion, altliough generally 

 accompanied by it. Nothing is easier than for any one to 

 convince himself of the fact that arterial congestion may exist 

 without inflammation. Let him put his hand into warm water 

 for a little while, and on taking it out he will find the whole 

 skin of a uniform rosy-red, showing that all the capillaries are 

 dilated and filled with bright blood ; the veins will swell up, 



