OF CURRENT FORCE DURING SECRETION. 
251 
Explanation of the Woodcut. 
Fig. 1. Wooden mercurial cup. 
Fig. 2. Copper wire to form the communication between the galvanometer and 
mercury. 
Fig. 3. A section of the mercurial cup, showing the mode in which the thick copper 
wire was connected with it. 
Fig. 4. Shows the manner in which the plate of platinum was soldered on to the 
platinum electrode, pure gold being used ; all the part within the dotted 
line, and for a short distance up the wire, was coated with shell-lac to pre- 
vent the action of the mercury upon it. 
Fig. 5. Electrode A. Fig. 6. Electrode B. Fig. 7. Electrode C. 
Fig. 8. The arrangement with the galvanometer previous to each experiment. 
Fig'. 9. a a a, arteries ; h h h, veins ; the arrows indicate the course of the blood : 
c, point of the electrode in contact with the wounded vein ; the dotted line of 
d the electrode in contact with the mucous surface of the small intestine. 
2 L 
MDCCCXLVIir. 
