Class II. i. 2. 4. OF SENSATION. iG 9 



attends the infpirations in the latter, and there was no attendant 

 fever; and the difeafe was cured by one venefectaon, and a 

 moderate dofe of opium after the venefe&ion. bee afthma 

 convulfivum. Oafs III. 1. 1. 10. 



A convulfive difficulty of refpiration may thus be eafily dif- 

 tinguifhed from the croup ; as in the former the patient draws 

 in the breath eafily, and then voluntarily clofes the larynx, and 

 voluntarily ufes great exertion in forcing out the breath, with 

 defign to relieve fome pain by this violent exertion, as in parox- 

 yfms of epilepfy. 



On the contrary, in the croup the breath is eafily expired, 

 but the infpirations are attended with the utmoft difficulty. 

 This difficulty of infpiration may be feen by viewing the region 

 of the ftomach ; as when the child raifes the fternum for the 

 purpofe of drawing in its breath, the preflurs of the atmof- 

 phere on the pit of the ftomach prefTes the diaphragm upwards, 

 and makes a fudden and great hollow in the fcrobiculus cordis. 

 This difficulty of infpiration, and not of expiration, is alfo known 

 by the harm found, which only attends the infpiration. 



This difficulty of infpiration may in part be owing to this cir- 

 cumftance. In difTe&ing thofe children who have died of the 

 croup, I believe the upper part of the adherent coagulable lymph, 

 or indurated mucus, formed within the trachea, is found to be- 

 come loofe, and to ieparate from the upper part of the trachea 

 before the lower part of that adhefive membranous croft begins 

 to feparate, and hence the loofe upper part at the time of infpira- 

 tion is bent downwards into the trachea, and thus becomes dou- 

 ble, and obftructs the paffage ; but this duplicature of it does 

 not happen in expiration. See Tranfa6r. of a Society, Vol. II. 

 Account of Croup, by Henry Ramfey, cafe the 8th. Might not 

 this be prevented from being fatal, by an apercure into the wind- 

 pipe beneath the larynx ? 



I have very lately leen a meft diftincl cafe of this peripneu- 

 monia trachealis, or croup. The child, about ten months old, 

 had great difficulty in drawing in its breath, with much noife ; 

 but had much lefs difficulty in its expiration, with little or gener- 

 ally no found- On obferving its naked cheft, the fternum, or 

 breaft-bone, was feen to be raifed with great force 5 and then the 

 diaphragm, and the bowels under it, rofe haftily up into the low- 

 er part of the cavity of the cheft ; and the air rufhed with diffi- 

 culty, and with great found, through the contracted larynx into 

 the upper part of the cheft ; both thefe effects were evidently 

 owing to the preflure of the atmofphere, to fupply the vacuity, 

 which muft ctherwife fucceed the forcibly railing of the fternum. 



Why the difficulty of infpiring. was fo much greater than 



Vox. 11. y of 



