Cuss II. 1. 2. 4. OF SENSATION, 169 



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

 fever; and the disease was cured by one venesection, and a 

 moderate dose of opium after the venesection. See asthma con- 

 vulsivum. Class III. 1. 1. 10. 



A convulsive difficulty of respiration may thus be easily dis- 

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

 in the breath easily, and then voluntarily closes the larynx, and 

 voluntarily uses great exertion in forcing out the breath, with de- 

 sign to relieve some pain by this violent exertion, as in paroxysms 

 of epilepsy. 



On the contrary, in the croup the breath is easily expired, but 

 the inspirations are attended with the utmost difficulty. This 

 difficulty of inspiration may be seen by viewing the region of the 

 stomach; as when the child raises the sternum for the purpose of 

 drawing in its breath, the pressure of the atmosphere on the pit 

 of the stomach presses the diaphragm upwards, and makes a sud- 

 den and great hollow in the scrobiculus cordis. This difficulty of 

 inspiration, and not of expiration, is also known by the harsh 

 sound, which only attends the inspiration. 



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

 cumstance. In dissecting those 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 loose, and to separate from the upper part of the trachea 

 before the lower part of that adhesive membranous crust begins 

 to separate, and hence the loose upper part at the time of inspira- 

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

 ble, and obstructs the passage; but this duplicature of it does not 

 happen in expiration. See Transact, of a Society, Vol. II. Ac- 

 count of Croup, by Henry Ramsey, case the 8th. Might not this 

 be prevented from being fatal, by an aperture into the windpipe 

 beneath the larynx? 



I have very lately seen a most distinct case of this peripneu- 

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

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

 but had much less difficulty in its expiration, with little or gene- 

 rally no sound. On observing its naked chest, the sternum, or 

 breast-bone, was seen to be raised with great force; and then the 

 diaphragm, and the bowels under it, rose hastily up into the lower 

 part of the cavity of the chest; and the air rushed with difficulty, 

 and with great sound, through the contracted larynx into the upper 

 part of the chest; both these effects were evidently owing to the 

 pressure of the atmosphere, to supply the vacuity, which must 

 otherwise succeed the forcibly raising of the sternum. 



Why the difficulty of inspiring was so much greater than 



VOL. If. Z 



