118 MORBID DISEASES. [BOOK I. 



Here, however, let him stop a little, and consider 

 awhile; for, upon his rightly understanding what 

 now becomes of the blood (thick, dark, and un- 

 serviceable as it is), and how, in a trice, it becomes 

 healthy, of a bright scarlet colour, and invigorating, 

 mainly depends his being able to comprehend, by- 

 and-by, what we shall have to offer concerning the 

 diseases to which a vitiated or corrupt state of the 

 blood gives rise. He will not, otherwise, make 

 out sufficiently clear in what manner the blood of 

 an animal can contract and retain that morbid state 

 which shall pre-dispose it towards acquiring a con- 

 stitutional disease that, however differently named 

 according to the parts whereon it may fix, has but 

 this one common origin for the entire series. To 

 this page, then, we shall frequently refer him, when 

 speaking to these points more in detail, hereafter ; 

 and he had best way, also, keep the book open at 

 this place, whenever he may be endeavouring to 

 comprehend what the learned veterinarians of the 

 present day are striving to say respecting " the cir- 

 culation," as they quaintly term it. Another of 

 them, speaking upon the topic just brought to a 

 conclusion, says, " The heart is divided into two 

 cavities, termed ventricles, each having an auricle, 

 resembling a dog's ear. The blood-vessels proceed 

 from these [those] cavities, the arteries from the 

 ventricles, the veins from the auricles," &c. All 

 which is very true, but not very intelligible to the 

 generality of readers ; and yet is the author, who 

 thus speaks, (Mr. White, in vol. i. p. 63.) fully 



