SEMIOLOGY. 15 



diiced by the forcible expulsion of the air through the closed 

 glottis, generally attendant on direct irritation of the respira- 

 tory organs as stated, but not always, seeing we knoAv cough 

 may result from dental or gastric disturbance. This cough 

 when existing must not merely be observed, but its character 

 must be noted. When moist, it is usually associated with 

 such diseased conditions of the mucous membrane of the air- 

 passages as common catarrh, or some forms of bronchitis or 

 laryngitis, where the secretion of the membrane has been much 

 increased. When hard, dry, and painful, the inflammatory 

 action in the air-tubes and passages is of the non-secretory 

 character, as in the earlier stages of the greater number of the 

 diseases aft'ecting these. While when accompanying inflamma- 

 tions of the serous membrane of the chest, its short, suppressed, 

 and painful character is very striking, being evidently emitted 

 spasmodically in spite of efforts to suppress it. 



Besides the careful observance of these symptoms associated 

 with the respiratory function, we must by physical examination, 

 by auscultation and percussion, endeavour to obtain some 

 knowledge of the changes steadily occurring to the central 

 organs and the thorax as a whole. 



3. Abdomen. — Here the direction of our inquiry and ex- 

 amination is chiefly with the view to discover the state of the 

 great natural secretions and evacuations. 



In not a few instances, particularly where disease is located 

 in the abdominal cavity and organs contained there, physical 

 changes, visible externally, will arrest our attention and supply 

 us with facts useful for our guidance. Chiefly, however, are 

 we to note the state of the functional activities of the organs 

 situated in this region as indices of the natural conditions. 

 Besides merely observing phenomena as presented to us, inquir}' 

 must be made as to the frequency and character of the intes- 

 tinal evacuations, and the discharge of urine. 



Tympany, with or without associated pain, points to indi- 

 gestion ; frequent and moist evacuations are indicative of irri- 

 tation of the villous surface of the digestive canal, and when 

 excessive, this state in the horse is always a more serious con- 

 dition than retention of the evacuations. Retention of fiecal 

 matter suggests disease of the bowels or liver, with more rarely 

 involvement of the kidneys and other gland-structures. 



