ON THE PHYSIOLOGY OF THE LUNGS AND AIR-TUBES. 417 
the dynameter for the first five minutes ; but after this it took 
effect, and raised the column two tenths; and in a quarter of 
an hour four tenths. These effects gradually diminished, and 
ceased in half an hour. 
16. About ten grains of extract of belladonna*, mixed with 
water, were injected into the jugular vein of a rabbit. In fifteen 
seconds, gasping with slight convulsions, and death in less than 
a minute. On opening the abdomen the heart was seen through 
the diaphragm acting quickly. The dynameter being adapted 
to the trachea, the chest was opened, when the column imme- 
diately rose two inches, and slowly an inch more, when it re- - 
mained stationary. Galvanism produced no effect for several’ 
minutes, and then a scarcely perceptible rise, which could not 
be re-induced, although the experiment was continued an hour. 
17. A dog was poisoned by mouth with hydrocyanic acid. 
He fell down howling in a minute and a half, and ceased to 
breathe in about halfaminute more. Heart beat strongly when 
the chest was opened. Galvanism raised the column of the dy- 
nameter two inches, and a similar but decreasing effect was ob- 
tained at times for half an hour. The same differences were 
observed in the contractility of different parts, as after death by 
pithing. The cut ends of the tubes continued to contract on 
being galvanised half an hour after death. 
18. About twenty drops of strong hydrocyanic acid were in- 
jected into the carotid artery of an ass about six months old. 
It immediately caused the breathing to become very deep and 
rare; but the effect passing off in about ten minutes, nearly a 
drachm more was injected. The deep convulsive breathing re- 
turned, with tetanic rigidity of the trunk and loud groaning. 
The breathing became very rare, whilst the heart beat violently 
with a double second sound. Death ensued about. three mi- 
nutes after the second injection. A small lobe of the lung when 
galvanised repeatedly raised the column three tenths. Sections 
of tubes in other parts contracted distinctly on being galvanised, 
but to a less extent than in the dog. Contractile motion was 
distinctly seen on cutting a cartilaginous ring of the trachea, 
and then galvanising the membranous portion at the back. 
19. About ten grains of extract of belladonna mixed with 
water, were injected into the right jugular vein of a large dog. 
Pupils began to dilate in fifteen seconds, and breathing more 
and more deep and laborious, accompanied with convulsive 
starts and howling. The breathing ceased and the eye became 
insensible two minutes after the injection. The integuments of 
* This and other extracts used were obtained from Mr. Squire, Chemist to 
the Queen. : ' 
1840. 25 
