138 PROFESSOR RUTHERFORD ON THE 
and the experiment was begun between nine and ten o'clock on the following 
morning, so that the digestion and absorption of the food were completed, and 
the animal was therefore in a fasting condition. This was an essential pre- 
liminary ; for, as is well known, the secretion of bile is accelerated during the 
process of digestion, and had we taken the amount of bile secreted per hour 
during digestion, as an index of the activity of the liver, previous to the 
administration of a drug, our experiments would necessarily have been worth- 
less. The disturbing effect of irregular muscular movements upon the biliary 
flow was prevented by injecting into a vein small doses of curara, repeated 
at intervals, when the motor paralysis which it induces became too slight. In 
consequence of the curara palsy, artificial respiration was had recourse to, and 
maintained at regular intervals throughout the whole experiment. Chloroform 
was used during the preliminary operation in two cases, but the stimulation of 
the liver which it induced rendered the experiments worthless.* On the other 
hand, we have abundantly proved that the doses of curara administered in the 
following experiments have no influence on the biliary secretion, and do not 
interfere with the effects of hepatic stimulants. It is, therefore, an exceedingly 
valuable auxiliary in a research of this nature. The method of experiment we 
adopted was always that of a temporary biliary fistula. Through an opening 
in the linea alba a glass cannula was inserted into the common bile duct near 
to its junction with the duodenum, and tied therein. To the end of the 
cannula projecting from the abdomen a short caoutchouc tube was attached, 
and to the free end of this a short glass tube drawn to a narrow aperture so 
that the bile might drop from it, as Rouric (Op. vi.) had recommended. The 
gall-bladder was then compressed, in order to fill the whole tubing with bile, 
and the cystic duct was clamped to prevent its return to the gall-bladder, and 
so compel all the bile secreted by the liver to flow through the cannula. The 
wound in the abdominal wall was then carefully closed, and in all save the 
earliest experiments the animal was thoroughly covered with cotton wool, in 
order to quickly restore it to its normal temperature; and guided by a ther- 
mometer in the abdominal cavity, great care was taken to keep the temperature 
normal,—a matter of no small importance,—for if the temperature fall several 
degrees, the liver secretes more slowly. 
The respiration requires to be maintained with regularity, otherwise the 
* Tt may be well to state, however, that in all the operations for the previous experiments on the 
action of cholagogues performed by Dr RuruErrorp twelve years ago, at a time when there was no 
antiphysiological excitement prevailing, chloroform was fully administered to every animal, because in 
those experiments the biliary fistula was of a permanent nature, and observations were not begun on the 
biliary secretion until some days after the operation—when of course the effect of the chloroform had 
completely passed off. The biliary fistula being of a temporary character in the present research, and 
the whole time taken up by each experiment being not more than a few hours, the use of anesthetics 
was inadmissible, 
