GRAPHIC OF ARTERIAL PRESSURE 31 



the needle into the vein fails by pricking the vein across or by missing and 

 simply entering a vein-sheath of connective tissue, it is best at once to with- 

 draw the point and re-enter the vein slightly higher up in the wound ; that 

 is why the vein should be employed at the lowest pai-t of the wound at first. 

 The introduction of the needle-point being satisfactory, the finger of the left 

 hand is withdrawn from compressing the vein above, and the syringe is 

 emptied as far as the piston-guard by pushing the handle with the little 

 finger of the right hand. 



If it be desired to inject more than one syringe-full the syringe nozzle is 

 freed from t he needle, which is left in the vein ; the syringe is refilled and 

 then reinserted into needle-base. When the injection is done the needle is 

 withdrawn and the vein is clamped at the pricked spot with a bull-dog clip, 

 if bleeding ensues, which usually is not the case. 



VIII. Inject with the needle-syringe per venam -5 c.c. of atropine Obs. 19. 

 sulphate sol. (1 per cent, diluted 5 times, i. e. 1 + 4 Ringer-Locke), i.e. 1 mg. ^^^^lysis of 

 atropine su Iphate. During, or within 8" of the completion of, the injection by atropine, 

 let the vagus stimulation be repeated with a strong stimulus. The inhibitory 



effect will have disappeared. 



IX. Have ready (1) in a small basin 50 c.c. strong salt solution, e. g. Obs. 20. 

 sodium chloride added to excess to 50 c.c. warm water ; soak in it some cotton- ■^^'t®riai 

 wool, squeezing out the air so as to soak it thoroughly. (2) The small faradization of 

 thin copper plate provided with binding-screw attached. (3) The single-wire the spinal cord, 

 electrode in a stylo-penholder as provided (PI. VI, fig. 4), with a binding- 

 screw on the handle end. (4) The short bandage provided. 



Wet thoroughly the toe-pads and cushions of one hind foot of the 

 preparation with the strong salt solution. Apply a squeezed-out thin pad of 

 the cotton- wool soaked in strong saline to the planta and make the pad 

 press well against and between the toe-pads and cushions. Place over 

 the pad the copper plate, bending it to suit the shape of the foot, and 

 with the binding-screw outwards ; bind the plate firmly in position by means 

 of the bandage, leaving the binding-screw projecting; fix the bandage by 

 tying it. 



Remove the neck-stump clamp, unscrewing it from the atlas. Expose 

 the top severed end of the spinal cord by carefully removing the pledget 

 of cotton- wool so as to avoid restarting haemorrhage there. Arrange the 

 neck-stump on the operation table so that the preparation lies without 

 disturbance to the arterial-pressure connexion with the manometer. 



Connect with an insulated wire the binding-screw on the copperplate 



