220 PBELIMINAET EEMAEKS. 



Inflammation of the Lungs, Bronchitis, Plexirisy, and other 

 inflammatory diseases of the respiratory organs, may exist, each 

 in a pure and distinct form ; but eases of this nature, com- 

 paratively speaking, are rare : therefore, in treating upon one 

 disease, I am compelled, to a certain extent, to generalize my 

 statements ; and hence the difficulty to the amateur in obtaining 

 that clearness so desirable upon the matter. Be it remembered, 

 however, that the difficulties are not of my creating ; they exist 

 in the subject itself I do not write to mystify, but, if possible, 

 to make clear. 



The class of organs known as the respiratory are varied in 

 cliaracter, highly vascular, complex in structure, and fulfil a 

 duty in the animal economy of at least equal importance to any 

 other class of organs engaged in the maintenance of the life of 

 the horse. 



The organs proper and subsidiary to this class are, the nasal 

 passages, the larynx, the trachea, the bronchial tubes, and the 

 lungs ; also, the bony apparatus of the chest, which comprises 

 the ribs situated laterally ; the sternum, or the breast bone 

 situated anteriorily ; and a portion of the spinal column situ- 

 ated superiorUy ; also the muscles, which chiefly consist of the 

 intercostals, or the muscles of the ribs, and the diaphragm . 

 also the respiratory nerves, the principal of which are the ^ar 

 vaga, or the eighth pair. 



Every one of the organs enumerated is subject to various 

 forms of disease, many of which are of a violent and dangerous 

 character. 



The nasal passages are frequently the seat of Catarrh ; occa^ 

 sionally of a disease called Ozena (an afiection not hitherto 

 properly treated upon), and which I hope, in the course of the 

 present section, to describe intelligibly to the reader ; also of 

 Glanders, Polipi, and of Bpistaxis, or bleeding of the nose. 



