DISEASES G-LASS II. 1, 2. 4 



of expiring, requires to be further explained. During inspira* 

 lion, the pressure of the atmosphere, when the cavity of the chest 

 is enlarged by raising the sternum, and depressing the diaphragm* 

 acts upon the external part of the larynx, as well as on the aper- 

 ture of it, and thus contracts it, and assists the disease; whereas 

 in expiration there is no increase of atmospheric pressure on the 

 outside of the larynx, or trachea, to prevent the exclusion of the 

 air. In the same manner, if a flexible pipe of soft leather was 

 extended upwards a few inches through the bottom of a bucket of 

 water, but very little of the water could be discharged by it; as 

 the pressure on its sides would soon compress the pipe, and thus 

 stop up its mouth. 



After repeated venesection, and a cathartic of calomel, a blister 

 was applied on each side of the larynx, and the difficulty of breath- 

 ing became greatly relieved; and though the child had intervals 

 of easier respiration, and without noise, yet it died on the suc- 

 ceeding day. 



Where the difficulty of breathing is very urgent in the croup, 

 bronchotomy is recommended by Mr. Field. Memoirs of a Medi- 

 cal Society, London, 1773, Vol. IV. 



After repeated vensection, and cathartics, perhaps a drop or two 

 drops of tincture of opium, about six in the evening, might be of 

 use to prevent the return of the evening paroxysm, and this espe- 

 cially if the difficulty of respiration has an interval or remission, 

 as mentioned below. 



A strong decoction of seneca root is recommended by Dr. 

 Archer, of America. He boils half an ounce of the root, from 

 eight ounces of water to four, and gives a tea-spoonful every hour 

 or half hour, so as to produce vomiting or purging, and then gives 

 it in smaller quantities. He also rubs mercurial ointment about 

 the throat, and uses calomel internally, so as to affect the glands 

 of the throat as quickly as possible, when the disease is more 

 advanced, and the difficulty of breathing with harsh and shrill 

 inspiration is more urgent. Medical and Physical Journal, No. I. 

 p. 83. As a decoction of seneca root particularly stimulates 

 some parts of the throat, occasioning a disagreeable sensation in 

 it, it may in some cases contribute to loosen or discharge the adhe- 

 sive coagulable lymph, which has been secreted on the inflamed 

 membrane of the wind-pipe, and occasions the difficulty of in- 

 spiration by contracting its aperture; and may therefore be worth 

 trial after repeated venesection, and cathartics, and blisters on 

 each side of the throat. 



Dr. Wichmann of Hanover, above mentioned, asserts, that in 

 the croup the disease continues regularly to increase, from the 

 commencement of it, without intervals *of relief from the great 



