606 The Philippine Journal of Science 1922 
was very marked and recovery occurred only twenty-five minutes 
after the injection. The recovery of the vagus nerve from 
the second injection of this larger dose was delayed to forty- 
two minutes. 
ACTION ON THE ISOLATED INTESTINE 
The action of Datura alba on the intestinal movements was 
studied by suspending a 2-centimeter piece of small intestine 
of cat in 30 mils of Ringer-Locke’s solution contained in a 
muscle warmer. The muscle warmer was placed in a water 
bath which was kept at 38° to 40° C. The Ringer-Locke’s solu- 
tion was supplied with bubbles of oxygen throughout the experi- 
ment. One end of the intestine was fixed at the bottom of the 
solution, while the other end was attached to a heart lever for 
tracing. A rise in tracing indicates a contraction of the in- 
testine while a lowering indicates relaxation. Plate 1, fig. 1, 
shows the record of one of our experiments. 
The effect on the intestinal movement was not constant. 
With fresh intestine, contracting rhythmically, addition of Da- 
tura alba to the Ringer-Locke’s solution generally . produced 
relaxation and cessation of contraction. If the intestine was 
left in the solution, spontaneous and usually regular intestinal 
contraction appeared. An additional amount of Datura alba at 
this time did not alter the contraction. If, soon after cessation 
of intestinal movement, the solution was changed and contrac- 
tion again established, the addition of pilocarpine produced re- 
latively slight stimulation. Intestinal movement produced by 
pilocarpine was overcome by Datura alba. It is assumed that 
the site of action of pilocarpine in the intestine is the vagus 
_ ends. To counteract this effect of pilocarpine, Datwra alba must 
paralyze either the ends of the vagus nerves in the intestine or 
the intestinal muscle, or must stimulate the sympathetic inhib- 
itory mechanism. The muscle was not paralyzed, for it could 
still contract on mechanical stimulation. 
STRENGTH OF THE PREPARATION 
To determine the strength of Datura alba, we compared its 
effect on the inhibitory function of the right vagus nerve with 
the effect of atropine, of hyoscine, and of hyoscyamine. The 
vagus was stimulated with a Harvard inductorium whose second- 
ary coil was set, throughout the experiment, at 6-centimeter 
distance. The results we obtained in this experiment are shown 
in Plate 1, fig. 2. According to this experiment 0.0005 mil of 
