524 QUANTITIES OF ELECTRICITY APPRECIABLE BY THE BALANCE. 
Dr. Hodgkin and Dr. Roupell have 
detailed a series of experiments and 
observations relative to the specific mode 
of action of acrid poisons, which, 
whether at once introduced into the sto- 
mach, or the circulation, by injection 
into the veins, seem to operate primarily 
in the same manner as irritants to the 
mucous membrane. The Dublin Sub- 
committee, appointed for the purpose, 
have given in a report connected with a 
subject of great pathological interest, 
respecting which none but the experien- 
ced medical practitioner ought to pretend 
to p^ss a decided judgment ; — neverthe- 
less, when I look back to the early 
period of my own professional studies, 
and recollect the obscurity in which 
diseases of the heart appeared then to 
be involved, when their remedy seemed 
so desperate, as to suggest to one of the 
most distinguished writers on the subject 
the motto ‘ Hcsret lateri lethalis arundo' 
as appropriate to his work and as signi- 
ficant of the probabilities of cure, and 
when their very nature was known but 
partially, and could only be guessed at 
by methods purely empirical, — when I 
recollect all this, I cannot refrain from 
congratulating those of my brethern who 
are engaged in the duties of the profes- 
sion from which I am myself a deserter, 
on the discovery of a new instrument of 
investigation in diseases of this nature, 
the use of which being founded on phy- 
siological principles, seem susceptible of 
greater improvement and more extended 
application in proportion as our know- 
ledge of the animal economy advances. 
But in order properly to avail our- 
selves of the indications of desease af- 
forded by the differences of sound trans- 
mitted through the integuments by the 
heart, it is necessary that we should be 
acquainted with the nature of its pulsa- 
tions, and of the sounds occasioned by 
them in a healthy state, and this infor- 
mation it has been the object of the Dub- 
lin Sub-committee to embody in the 
report which was communicated by them 
last year to the Medical Section. 
Such are the principle contents of the 
volume which records the scientific la- 
bours instituted at the express sugges- 
tion of the general body, and prepared 
for its last Meeting ; but, exclusively of 
these, many very valuable and elaborate 
investigations were submitted to the 
several Sections without any such soli- 
citation. 
I may instance in particular the views 
with respect to the classification and the 
geological distribution of Fishes, ex- 
pounded to us with so much ability by 
Mons. Agassiz, whose important labour 
might perhaps have been suspended, 
but for the timely assistance dealt out to 
him by this bod5% and the opportunities 
which its Meetings afforded, for giving 
them that publicity which they deserved- 
I may point out likewise the impor- 
tant results submitted to the Geological 
Section by Mr. Murchison and Profes- j 
sor Sedgwick, with reference to the Si- i 
lurian formations of Wales and Shrop- ! 
shire, and the multitude of facts illus- 
trative of the physical structure of Ire- j 
land, which were elicited by the exhibi- ' 
tion of Mr. Griffith’s Geological Map» | 
an undertaking which, coupled with the | 
researches of Mr. Mackay on the plants i 
indigenous to that country, promises to i 
render us as w’ell acquainted with the i 
Natural History of this portion of the i 
Empire, as we already are with respect i 
to Great Britain itself. 
Nor must I forget the researches on 
Comparative Anatomy laid before the ;i 
Medical Section by Dr. Houston, who | 
pointed out the existence of reservoirs | 
connected with the veins leading to the ( 
lungs in the Cetacea, an admirable con- [ 
trivance, by which Nature has provided I 
for the unobstructed circulation of their 
blood, in spite of the enormous pressure i 
which they have to sustain at the great I 
depths to which they are wont to 
dive. 
The Members of the Association had I 
also the satisfaction of witnessing the , 
ingenious manner in w'hich Mr. Snow | 
Harris contrives to render quantities of |! 
Electricity appreciable by the balance, I 
like those of any gross material sub- 
stance ; whilst such as could enter 
upon the more refined branches of i 
mathematical analysis must have listen- ] 
ed with profound interest to the exposi- j 
tion given by Professor Hamilton, of | 
the ingenious labours of Jerrand, of 
this city, in solving Equations of the 
higher orders. i; 
What proportion of such inquiries 
may be attributable to the influence of p 
this Association, and how much might 
have been merely the result of that in- : 
creased taste for physical research to I 
which the Association itself owes its 
existence, I do not pretend to determine j j 
this however, at least, must be allowed, ; 
