CHAP. II.] COURSE OF STUDY. THE LUNGS. 99 



pulsion of the air, forming the re-action, being 

 termed expiration ; both together constitute what 

 we call breathing or respiration, and the matter 

 was before introduced (in section 26.) when we 

 noticed that powerful auxiliary of this function — 

 the midriff. Now, as we have always attached 

 much importance to the act of respiration, seeing 

 its close connexion with the formation of blood, and 

 the almost constant state of disease in which are 

 found the organs that contribute to this great func- 

 tion of animal life, we shall enter into more minute 

 particulars respecting these, than we have thought 

 necessary for any of the preceding organs. By this 

 course, the reader will be enabled to form more dis- 

 tinct notions respecting the forming and " circula- 

 tion of the blood," and its concomitant, the forma- 

 tion of chyle, commonly called " the Digestive 

 powers" — both of them functions most essential to 

 health ; but, unhappily, both together become, by 

 contravention of those powers, the fruitful source 

 of numberless ills, we thence call constitutional or 

 bodily disease, as fever, abscess, farcy, &c. To this 

 point tends all that we have hitherto said concern- 

 ing the inside of the horse ; and the inquirer after 

 veterinary knowledge will find his labour in study- 

 ing this portion of it amply repaid, by the just 

 principles upon which he will subsequently conduct 

 his practice. 



32. The lungs, or lights, are two well-known 

 spongy bodies (i. e. lobes), having at their con- 

 junction a small lobe nearer to where the pipe 



f 2 



