510 Dr. Davy’s observations and experiments 
alarming symptoms, by perforating the chest, and allowing 
the accumulated air to escape. 
Patrick Calnon, of the 50th regiment of Foot, was ad- 
mitted into the medical division of the General Military Hos- 
pital, at Fort Pitt, on the 9th of May last, immediately on 
his return from Jamaica, from whence he was sent home 
invalided on account of hemoptysis, produced by a severe fall 
on the left side of the chest, 18 months ago, previous to which 
accident he had enjoyed uninterrupted good health. 
Till the 13th of May his complaint exhibited nothing 
peculiar. Early on the morning of that day, after a violent 
fit of coughing, the symptoms of pneumato-thorax began to 
appear, and they continued to increase till the 21st. The 
most prominent symptoms were, a feeling of extreme tight- 
ness about the chest and abdomen ; rapid and difficult respi- 
ration, between 30 and 40 in a minute ; great anxiety of 
countenance and agitation of mind, accompanied with a small 
pulse of 130 ; cold sweats frequently breaking out on the 
face and neck ; and a considerable prostration of strength. On 
examining the chest, the left side was found more protuberant, 
and in all its dimensions larger than the right ; it was tense, 
and on percussion sounded remarkably hollow and tympanitic,, 
giving the idea of its being distended with air ; and the heart 
was found beating on the right side under the mamilla. 
In consultation with Dr. Skey, Physician to the Forces, and 
Mr. Schetkey, Surgeon to the Forces, the operation of tapping 
the chest, which I recommended, was approved of, and, with 
the consent of the patient, immediately performed. 
With a small trochar, attached to a flaccid bladder, I care- 
fully perforated the left side of the chest, between the 8th 
