412 REPORT—1840. 
treatment of various diseases of the respiratory organs, espe- 
cially asthma, is at present founded on the supposition of a 
muscular contractility of the air-tubes, the very existence of 
which is stated by one of the most eminent of modern physio- 
logists to be little more than assumed. The chief objects of the 
following experiments were to test the existence of muscular 
irritability in the air-tubes ; and if such were present, to deter- 
mine its character, and the circumstances or influences which 
could affect or disturb it. The experiments were performed at 
the London University College, and in several of them I was 
kindly assisted by Professor Sharpey, Mr. James Blake, Dr. 
Davison, and several of my pupils, especially Messrs. Blom- 
field, Carlill, Parkes and Jos. King. 
In most of the experiments I made use of Poiseuille’s 
hemadynamometer, which is a tube bent like an inverted si- 
phon, containing a coloured fluid; the short limb of this tube, 
furnished with stop-cocks, being adapted to the windpipe or one 
of its branches, the column of fluid within would be readily 
moved by any contraction of the air-tubes or lungs, causing pres- 
sure on the air in it: and the rise or fall of this fluid was mea- 
sured by a scale divided into inches and tenths. 
1. A dog was killed by pithing. The chest being imme- 
diately opened, the lungs collapsed completely. They were 
taken out with a part of the trachea, which was then tied to the 
brass tube of the hemadynamometer (or as I shall call it, the 
dynameter) ; on completing the communication by turning the 
stop-cock, the fluid in the tube oscillated several times to the 
amount of about one fourth of an inch. On passing a galvanic 
current, from a trough of thirty three-inch plates, from the margin 
of the lungs to the brass tube in the trachea, the fluid rose 
quickly, but gradually, nearly two inches; it sunk speedily on 
breaking contact ; again rose on repeating it; but fell slowly 
when the contact was continued for some seconds. When the 
current was passed only through a single lobe, the rise was still 
distinct, amounting to three or four tenths of an inch. The 
rise was repeatedly produced, but to a diminishing extent, and 
after two or three minutes the effect seemed to be exhausted. 
2, The preceding experiment was repeated with eight dogs 
of various sizes, with similar results. The rise of the fluid co- 
lumn caused by galvanising the whole lung amounted at first to 
from 14 to 2} inches, but afterwards gradually diminished. If 
the current was passed continuously for some length of time, 
the fluid in the tube fell, and could not be raised by the gal- 
vanism for a minute or two after. It was found also that inflating 
the lungs impaired the effect of the current. On repeating the 
