656 
The Function of the Iris. 
It has been veiy generally believed that the iris derives its 
contractile power from the influence of the optic nerve, or retina; 
and hence it has been recommended not to operate for cataract, 
especially when extraction is necessary, if the iris appears motion¬ 
less. The author (Larrey), however, opposes this doctrine by 
arguments numerous, if not convincing; and contends that the 
properties of this membrane depend exclusively on its own tex¬ 
ture, and on the ciliary nerves which are sent to it from the lenti¬ 
cular ganglion of the great sympathetic. Cases of amaurosis, he 
argues, are met with, in which the iris retains its contractility— 
wounds inflicted on the nerves, by which its mobility is supplied, 
have palsied this membrane, while the faculty of sight remained 
unaffected; and belladonna suspends its contractility without 
disturbing any other function of the eye ;—these and other argu¬ 
ments, which are illustrated by cases, but to which we can only 
refer, are urged by Larrey to prove that the iris is independent, in 
all its functions, of the optic nerve.— Med . Chir. Rev. July 1831. 
The Function of Absorption exercised by the 
Capillary Veins. 
The experiments of Hunter, made by exposing and isolating 
small portions of the intestines of living animals, filling them 
with different fluids, chiefly milk and a solution of indigo, and 
then examining the contents of the lacteals, and of the veins 
leading from them, may be allowed to prove two points: 1st, 
That absorption, at least of milk, and probably of other fluids 
different from chyle, took place in his trials by the lacteals; 
2dly, That no absorption could be ascertained, in his trials, to 
have taken place by the veins. 
The first of these, which is a positive observation, although 
opposed to the results obtained by Magendie and others, agrees 
with the results of many other experiments, by Lister, Haller, 
Blumenbach, Tiedemann and Gmelin, Lawrence and Coates, 
and Fcedera, in which it appeared that a certain portion of dif¬ 
ferent fluids, introduced into the intestines, was taken up by the 
lacteals; and the possibility of their absorbing fluids different 
from chyle may, therefore, be held to be decided. But the 
second observation of Mr. Hunter, which is a negative one, is 
quite an insufficient ground for the general conclusion, that veins 
do not absorb; and the reality of venous absorption is now put 
