I have a beautiful silver queen that I have had for years and years. It is very large and has always done very well for me with little maintenance. Anyway, this morning I walked past it pulled off a few yellow leaves and felt a sticky substance on a few stalks and other leaves. What is this?

There aren't any visible insects either on the leaves or in the soil. It is clear in color and very sticky.

Thank you

Your plant may have a pest problem, maybe mealy bugs or scale, Look for small white cottony waxy looking things around the stems (mealy bugs) or small slightly raised brownish colored bumps on mostly backs of leaves and on the stems (scale)or any other plant sucking pest. The sticky stuff is called honey dew (pest secretions) Look under PLANT PEST for a picture of both these pest.

You'll need to spray the plant down thoroughly (dripping wet) with a solution of rubbing alcohol and water from a spray bottle. An inch of alcohol, the rest water.
Repeat every 5-7 days or so for three weeks, cover soil, after that, keep an eye out in case you missed any. Missing any can mean a re-investigation. Keep any other healthy plants away.