ward into the bladder; withdraw the trocar, and allow the urine to flow. In order to prevent the escape of urine into the tissues, take the same precautions as before, while removing the canula.

Rectal. Place the subject in the lithotomy position. Introduce the left index-finger into the rectum, and feel for the prostate, and then feel beyond a space bounded on each side by the cord-like vesiculæ seminales converging toward the prostate. Introduce a curved trocar and canula with the convexity downward, and the point of the trocar sheathed in the canula, along the palmar surface of the finger until the end of the canula is applied to the anterior rectal wall just beyond the prostate in the median line. Protrude the point of the trocar, and push the instrument upward into the bladder. Do not allow urine to escape from the canula while the canula is being withdrawn.

Paracentesis Urethra.-Place the subject in the lithotomy position. Introduce the left index-finger into the rectum, and apply the pulp of the finger to the rectal wall where the anterior extremity or apex of the prostate is felt. With a double-edged knife held as a pen, but with cutting edges held vertically, pierce the perinæum in the median line a little less than an inch in front of the anus. Push the knife boldly forward, directing the point toward the tip of the left index-finger. The knife may be given a slight upand-down motion of the handle to enlarge the wound as the point advances; when the point is felt to be near the tip of the finger, by directing it obliquely to the right or left, the urethra is opened.

To catheterize through this puncture, withdraw

the knife and insert a director into the bladder, when the left index-finger can be removed from the rectum, and the left hand given charge of the director. On the director guide a catheter into the bladder.

If the urethra is tapped through the rectum, the lateral walls of the rectum may be held apart by two Sims's specula, and the left index-finger must direct the point of the knife toward the apex of the prostate.

Aspiration (Dieulafoy).-Draw the piston back, producing thus a vacuum in the cylinder of the instrument. Grasp the needle in the same manner as a trocar, and push it through the skin and tissues into the cavity to be explored. If its use is substituted for the trocar and canula, the direction and situation of the punctures are the same for both instruments. By drawing the skin to one side before making the puncture, the opening in the skin on removing the needle will not correspond with the course of the needle through the deeper tissues, thus presenting a valvular arrangement against the entrance of air. After the opening in the needle is buried in the tissues, open the stop-cock, which will cause the vacuum to extend into the needle. Now advance slowly, "vacuum in hand," in search of the effusion. As soon as a cavity is entered, the point of the needle must remain stationary until the needle is removed.

II. HYPODERMIC NEEDLE.

The hypodermic needle should always be made use of before the trocar and canula as a means of diag nosis. It must enter the same spot, and have its point directed as that of the trocar in the various tappings. Withdraw the piston after the point is in the fluid,

and allow the syringe to fill. The needle must be withdrawn quickly, and the left index-finger placed immediately over the point of puncture.

If the needle is used for medication, the manipulation is different. Put the nozzle of the syringe into the solution to be injected, and withdraw the piston beyond the mark denoting the required number of minims. Adjust the needle, and force out the superfluous solution and air, holding the syringe with the point upward.

If the medication is special, the point of the needle is introduced to the spot, and the syringe slowly emptied. If the medication is general, the skin and areolar tissue are pinched up preferably on the outer side of the arm or thigh into a fold about one quar ter of an inch broad. The needle is entered in front of and between the tips of the left thumb and indexfinger which are holding the fold, avoiding veins, and pushed obliquely downward until the sensation is obtained that the point is in loose tissue. Slowly inject the fluid. Withdraw the needle, and slightly rub the part, to diffuse the solution into a greater area of the areolar tissue.

CHAPTER III.

MANIPULATION OF THE SCALPEL.-DRAINAGE.—

SUTURES.-KNOTS.

MANIPULATION OF THE SCALPEL.

1. How to hold the Scalpel.-Three methods of holding the scalpel are necessary to graceful operation:

(a) The first is where the scalpel is held as a pen. The handle of the instrument passes upward to the radial side of the index-finger. The lower part of the handle and the upper part of the blade are held between the pulp of the thumb on one side, the index-finger on the back, and the middle finger overlapping the other side. The ring and middle fingers are semiflexed, and are used as rests to steady the hand.

This method is useful in the limited and precise cuts of a dissection.

The edge of the scalpel is turned forward when used to cut from within outward after puncturing, as in opening an abscess.

(b) The second method is where the scalpel is held like the bow of the violin. The direction of the instrument is almost parallel to the surface. The handle is held between the pulp of the thumb on

one side and the pulps of all the other fingers on the other. The pulp of the index-finger may be placed on the back of the blade if firmness is required.

This method allows the greatest freedom to the hand, hence is used in making long incisions.

In dividing tissue over the director, this method is used, with the edge turned upward. If the tissue is divided from the distal to the proximal end, the handle of the instrument points forward.

(c) In the third method the scalpel is held as a table-knife. The handle of the scalpel is kept against the palmar surface of the hand by the ends of the middle and ring fingers. The index-finger bears upon the back of the blade, while the thumb presses the instrument against the side of the middle finger.

This position allows a great deal of force to be exerted, as in separating muscular attachments from bones.

2. How to use the Scalpel; Incisions. The foregoing methods of holding the scalpel should be practiced while making incisions into the abdominal wall. Avoid incising the median line of the abdomen, in order not to interfere with other operations.

Enter the point of the scalpel perpendicularly where the incision is to begin, through the integument, stretched equally between the left index-finger and thumb. Lower the handle so that the belly of the scalpel will be applied to the tissues. Cut the integument without much pressure, but with slight sawing motion to the desired extent. The incision is completed as it was begun, with the scalpel held perpendicularly to avoid "tailing."

Incisions may be made by pinching up the skin,