516 BROKEN WIND. 



tion of these lesions to the pathognomonic dyspnea and to the 

 pecuhar manner in which the act of respiration is executed be 

 more easily understood. 



HoAvever, as it is tolerably certain that many cases during 

 life exhibit all the characteristic symptoms of broken-wind, 

 which on examination after death give no evidence of any of 

 these structural changes, we are compelled to believe that the 

 truly essential factor in the production of the distinctive 

 dyspncea and diagnostic expiration is not accounted for in 

 these explanations offered of the various phenomena connected 

 with this pulmonic tissue-change. 



2. Thus, although allowing that these textural changes of 

 the pulmonary tissue may in many instances be accepted as 

 sufficiently explanatory of the various morbid phenomena 

 cognizable to our senses and by our means of observation, it 

 seems that the acceptance of that other idea which regards 

 this condition as essentially a disturbance or perversion of 

 innervation consequent on certain dietetic conditions is more 

 capable of accounting for the many changes both of function 

 and structure, is less liable to objection, and as capable of in- 

 cluding and explaining in a great measure these tissue- 

 changes themselves. This view of regarding broken-wind — 

 often named asthma of the horse — as a disturbed condition of 

 innervation directly traceable to gastric and intestinal derange- 

 ment, although not new, has during the present generation 

 been more strongly insisted upon by various teachers and 

 writers on veterinary medicine ; and although not universally 

 received by those who have made the subject their study, is 

 that explanation of the causation of the disease which seems 

 most in accordance with observation and experiment. Con- 

 sidered as paralysis of lung-tissue of the reflex character, we 

 must look for the origin of the nervous disturbance in the 

 gastro-intestinal tract, where from irritation and the impress 

 of certain influences, partly mechanical, partly chemical, con- 

 veyed to the sensory nerves, and through them propagated 

 to the centres of innervation in the medulla and brain, the 

 influence so operating that the impulse or force conveyed 

 through the efferent branches of the same nerve, the pneumo- 

 gastric, becomes disturbed, perverted, or arrested in those 

 structures to which these branches proceed. 



