Quote Originally Posted by glassfire
i dunno where this embolism bs came from, but i can guarantee it is just as much a myth as that genetic drift fantasy (pseudo-science performed by not well educated guessers). h2o2 is the stuff for the problem, although if you lighten up on the water, it would help also!
You have seriously got to be kidding.

"With the cutting still submerged remove any excess leaves. If there are no internodes at the cut, make three or four shallow vertical slits (no deeper than the outer bark) upward from the cut along the stem about 1/2 inch. These cut must be made with the cutting submerged or air will be sucked into the stem causing what as know as an air embolism in which bubbles block the movement of water up the stem. An air embolism can cause death or slow the rooting process by weeks. This is known as the sip of life technique. By making all secondary cuts underwater, you eliminate air bubbles, reduce unnecessary strain on the clone and allow the cutting to stabilize in a fluid environment." source: http://www.drugs-forum.com/growfaq/1211.htm

On top of that, you can Google embolism and come up with a crapload of scientific papers on embolism in all types of plant tissues.