76 DISEASES OF THE LUNGS. 



convulsive efforts for breathy under certain bodily exertions, 

 such as racing, leaping, plunging, &c. Contusions from 

 falls or blows upon the side may injure the pleura ; fractures 

 of the ribs or sharp instruments may wound the pleura, or 

 lung, or both. And as for injuries of a chemical nature, in 

 this light may be viewed the several pollutions the atmo- 

 sphere of the stable receives from the effluvia of the dung, 

 the urine, and the breath of other horses. Ammoniacal 

 gas is said to prevail in the vapours from these excretions ; 

 and, consequently, there can be no question about the ope- 

 ration of such an atmosphere being highly excitant and 

 creative of inflammation. 



DIAGNOSIS. 

 Upon the diagnosis will the treatment depend. 



In the study and observation of diseases of the pulmonary 

 organs our chief aim must be to attain such intimate know- 

 ledge of them as will enable us not only to make the 

 necessary distinctions between them, but to so far ascertain 

 the nature and stage of each as to render us competent to 

 treat it under the circumstances, to the best advantage, and 

 at the same time give an opinion to be relied upon in regard 

 to its result. Certain symptoms are common to almost all 

 these diseases : that, however, which of all is, if not the most 

 common, the most important, is altered or disturbed respi- 

 ration. And there are so many degrees and kinds of altera- 

 tions in the breathing, that they of themselves, by attention 

 on our part, may be rendered of great value to us in the 

 formation of diagnosis. 



Respiration in health is shown by a placid, uniform, 

 regular, and hardly perceptible motion of the flanks, at the 

 rate, according to Delafond, of from 10 to 12 breathings a 

 minute in young horses, from 9 to 10 in old ; according to the 

 late Professor Sewell, of from 4 to 8. If horses in the stable 

 are referred to I cannot but regard the latter standard as 

 much too low. Delafond has given us what he calls a 

 *' synoptical table of the different kinds of respiration,^^ from 

 which we may gather some useful practical observations, with- 



