Various Causes of Noisy Respiration. 19 



symptoms (Lathyrismus) have been produced in mankind 

 by the Laihyrus sativus. 



One of the most marked symptoms of lead-poisoning in 

 horses, is the noise emitted in respiration when the animals 

 are moved at all quickly. Not long ago, in the neighbour- 

 hood of Bath, I saw a mare and her foal, which was only a 

 iew weeks old, so seriously affected in this way, that a little 

 excitement or rapid movement caused them great distress, 

 the inspiratory sound being loud and shrill. On the farm 

 where these animals were, and which was in close proximity 

 to lead-works, fowls, pigs, horses, and an ass had died from 

 lead-poisoning. Such instances are not at all rare, and 

 the paralysis of the larynx may be due to the action 

 of the lead upon the peripheral nerves of that organ 

 {neurotic cause), and perhaps also upon the muscles 

 {niyo2oathic cause). 



From these remarks it will be observed that noisy respira- 

 tion may be due to many causes, some of them of a tempo- 

 rary nature, others more or less permanent. The " Roaring " 

 may therefore be considered as " temporary," or " chronic " or 

 "permanent," according as it is ephemeral and depending 

 upon transitory causes, or continuous when the causes persist. 



" Temporary Roaring" may be developed during the course 

 of an acute disease of the larynx or the parts around it, or 

 it may arise from any casual obstacle to the entrance of air 

 to the lungs ; the kind and amount of noise varying with 

 the nature and intensity of the disease, or the character of 

 the obstacle which occasions it. It is generally readily 

 recognised, for not only is there usually a history of the 

 case to be referred to, but the sound itself often affords 

 valuable indications. This is in most cases of a rattling or 

 whistling kind, heard chiefly during inspiration, perceptible 

 at rest or in motion, and noticed not only at the nostrils and 

 on auscultation at the larynx, but also at some distance 

 from the animal. In extreme cases the respiration is 

 laborious and distressing ; the nostrils are widely dilated, 



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