OBSERVATIONS ON IRRITABILITY. 277
Does not the fudden flow of pale urine in hyfteric cafe, and of
the faliva in a hungry perfon upon the tafle or even upon the fight
of grateful food, fliew that the fecretory vefifels of the kidneys and
excretory duds of the falivary glands are, in fuch cafes, agitated
with an unufual ofcillatory motion, and confequently that they
have irritability ? Nor ought M. de Haller to have denied this power
to the vefifels of the kidneys and excretory duds of the glands : fince
he allows it to the lachrymal glands and mucous finufes, becaufe
they pour forth their fluids more copioufly when ftimulated ; al¬
though his experiments difcovered no figns of irritability in them
When a ftone pafifes from the kidneys to the bladder, does not
the irritation of the fliarp flone occafion fome fpafmodic con-
tradion in the ureter \ and does not a large dofe of opium faci¬
litate its pafiage, by abating or deftroying the painful feeling, and
confequently lefifening the conflridion of the ureter ? This canal,
therefore, feems to be pofifefled of fome kind of irritability, altho’
M. de Haller informs us that in the animals which he opened, it
was infenfible of theßimulus of oil of vitriol
If the learned author’s experiments difcovered no kind of irrita¬
bility in the blood-veflfels, ladeals, glands, and mucous finufes, it
will not follow that the ins has not that power, although it did not
feem to contrad when irritated with the point of a knife ||.
He adds, that the dilatation of the pupil cannot be owing to any
mufcular power, becaufe it becomes wideft at death or immediately
after §. I have elfewhere obferved that the dilatation of the pupil
is owing to the longitudinal fibres of the uvea, which, by their na¬
tural eontradility, draw back its edges, when the orbicular mufcle
is not excited into contradion by the adion of light on the retina #* ►
at death, therefore, when the eye is infenfible, the pupil becomes
« . wide ;
* A a. Gotting, vol. 2. p. 143. f ibid. p. 142.
$ As a further proof of this, my ingenious Colleague Dr Alexander Monro junior informs
me, that in a pig which was ltrangulated and half dead, he oDferved the ureter to con trad
*ery remarkably, when he touched it with the point of his finger; nay, when he moved the
point of his finger along the furface of the ureter, a fucceffive contradion of thnt canal was
produced from above downwards.
II Ad. Gotting, vol. 2. p. 143, § Ibid..
** Eflay on vital motions, fed. 7.