Page 62 - Joseph B. Healy "The Pocket Guide to Fishing Knots"

Surgeon’s Knot

1. You’re joining two pieces of line with this knot, so begin by
overlapping the tag ends by four to six inches. Make an overhand
knot loop in the overlapped line and pinch the junction of the loop
with your thumb and forefinger.
2. Make another overhand knot with the doubled line. Moisten this
connection with saliva—I usually pop the whole thing in my mouth—
which will help secure it when you pull tight.

3. Hold the heavy and light line and pull quickly and tightly. Be firm, be
decisive! Trim the tag ends.