CIRCULATION OF THE BLOOD. 129 



penetrative as when it is more serous and attenuated or liquid. 

 And then it seems only reasonable to think that the blood in 

 its circuit passes more slowly through the kidneys than through 

 the substance of the heart; more swiftly through the liver than 

 through the kidneys; through the spleen more quickly than 

 through the lungs, and through the lungs more speedily than 

 through any of the other viscera or the muscles, in proportion 

 always to the denseness or sponginess of the tissue of each. 



We may be permitted to take the same view of the influence 

 of age, sex, temperament, and habit of body, whether this be 

 hard or soft; of that of the ambient cold which condenses bo- 

 dies, and makes the veins in the extremities to shrink and al- 

 most to disappear, and deprives the surface both of colour and 

 heat; and also of that of meat and drink which render the 

 blood more watery, by supplying fresh nutritive matter. From 

 the veins, therefore, the blood flows more freely in phlebotomy 

 when the body is warm than when it is cold. We also observe the 

 signal influence of the affections of the mind when a timid person 

 is bled and happens to faint : immediately the flow of blood is ar- 

 rested, a deadly pallor overspreads the surface, the limbs stiffen, 

 the ears sing, the eyes are dazzled or blinded, and, as it were, 

 convulsed. But here I come upon a field where I might roam 

 freely and give myself up to speculation. And, indeed, such a 

 flood of light and truth breaks in upon me here ; occasion offers 

 of explaining so many problems, of resolving so many doubts, 

 of discovering the causes of so many slighter and more serious 

 diseases, and of suggesting remedies for their cure, that the sub- 

 ject seems almost to demand a separate treatise. And it will be 

 my business in my 'Medical Observations/ to lay before my 

 reader matter upon all these topics which shall be worthy of the 

 gravest consideration. 



And what indeed is more deserving of attention than the 

 fact that in almost every affection, appetite, hope, or fear, our 

 body suffers, the countenance changes, and the blood appears 

 to course hither and thither. In anger the eyes are fiery and 

 the pupils contracted; in modesty the cheeks are suffused with 

 blushes; in fear, and under a sense of infamy and of shame, 

 the face is pale, but the ears burn as if for the evil they heard 

 or were to hear; in lust how quickly is the member distended 

 with blood and erected ! But, above all, and this is of the 



