420 : REPORT—1840. 
of the latter, but less tardy than those of the former. (1, 2, 17, 
Sh Sec!) 
The irritability of the bronchial muscles is soon exhausted by 
the action of a stimulus (1, 2, 5, 12, &c.); and may in some 
degree be restored by rest, even when the lung is removed from 
the body for an hour or more (2, 3, 6). But when the stimula- 
tion is long continued, as by intense irritation of the mucous 
membrane during life, the irritability is not restored by rest, 
and the tonic contractility is also impaired (14). 
The contractility of the air-tubes seems to be much influenced 
by the mode of death ; having been for a time suspended after 
death by a blow on the back of the neck (5), and in one instance 
after death by pithing, and hemorrhage. Inflation of the lung 
also in some way suspends it for a while (2). 
Several vegetable poisons impair or destroy this contractility. 
Extracts of stramonium and belladonna produced this effect 
most completely (16, 19, 20). (Their superior efficacy in spas- 
modic asthma has been long known.) Strychnia, conium, and 
morphia also impair this property considerably (21, 22, 24, 25). 
Hydrocyanic acid, on the other hand, does not in any consider- 
able degree impair it (15, 17, 18). 
These poisons and different modes of death do not act on the 
irritability of the bronchial tubes in the same degree as they do 
on that of the heart and other contractile tissues, (22, 23, 24, 
25,) and they do not seem to act always equally on the irritable 
and on the tonic contractility of these tubes (25). ; 
The bronchial fibres seem to be excited more by direct sti- 
mulation than by any influence conveyed through the nerves of 
the lungs; for mechanical and galvanic irritation of the vagi had 
no effect on them ; and passing acurrent through the nerves to 
the lungs caused much less contraction than passing it through 
the trachea (4). 
I am well aware that these, and many other subjects connected 
with them, deserve a fuller investigation, and I have to regret 
that my engagements have prevented me from prosecuting them 
further. Such as they are I submit them to the consideration 
of the Section without dwelling on their practical bearings. 
Cuarues J. B. Wituiams, M.D., F.R.S., 
Professor of the Principles and Practice of Medicine, 
and Physician to the Hospital, London Univer- 
sity College. 
Holles Street, Cavendish Square, 
Sept. 15th, 1840. 
