NATURE. 515 



also whether every case of emphysema has been cohicident 

 with the phenomena usually understood to constitute broken- 

 Avind. 



From personal examination and observation, as well as from 

 what I have been able to glean from the experience of others, 

 there seems little doubt that emphysema, particularly the 

 vesicular form, does exist in many horses which have not at 

 any period exhibited symptoms indicative of the condition 

 known as broken-wind, also that a very large number of 

 notoriously broken- winded animals have, on post-mortem ex- 

 amination, shown, in an unmistakable manner, pulmonary 

 emphysema. Another, not such a numerous class, which 

 during life were undoubtedly sufferers from this affection, 

 did not, on after-death examination, give evidence of either 

 emphysema or other structural pulmonic changes. Further 

 than this, with respect to the connection and relation sub- 

 sisting between broken-wind and emphysema of lung-tissue, 

 post-mortem examinations will not permit us to go. 



This hypothesis was first enunciated in the end of the last 

 century, and was spoken of by the late Bracy Clark as having 

 originated in connection with the post-mortem examination of 

 an animal which had been sent to the London Veterinary 

 College to be destroyed on account of this disease. Although 

 when carefully handled it may afford a somewhat plausibl^ 

 rendering of the mode of operation by which these pulmonary 

 lesions may be regarded as inducing factors in the defective 

 respiration, it is not altogether free from objection, while the 

 various phenomena connected with the performance of the 

 morbid respiratory act are, we beheve, capable of a somewhat 

 different interpretation. 



Although we may not refuse to regard the emphysematous 

 condition of the lung-tissue in any other light than as an im- 

 pediment to the due performance of the respiratory act, as 

 also that probably the extent of respiratory derangement bears 

 a very close relation to the extent of this abnormal condition, 

 there is yet this to be remembered, that if the condition of 

 emphysema with alteration of air-cell tissue and thickened 

 mucous membrane, with an extra amount of secretion in the 

 minute tubes, were the invariable accompaniment of the 

 diseased condition known as broken-wind, then would the rela- 



33—2 



