You have to have a wand in the table (you'll see it floating above it), and another to use in the recipe.
lol @ Horrible Baby Spider Tree waypoint
If you have a wand of the apprentice in the wand slot of the infusion altar, as well as one in its crafting grid, you should see a wand floating on the altar and particles coming off the crucible going into the altar. Once an aspect of the recipe has been satisfied, it'll stop pulsating and turn fully opaque in the bottom part of the infusion altar. Rather than spending nonrenewable vis shards in your crucible, you could get the praecantatio the recipe needs from 16 chiseled sandstone. You'll get some extra solum and saxum spilling out as flux, but it's much cheaper than using shards.
Actually, shards are renuable because you can use crystal clusters to overcharge your node, which than makes infused stone out of stone.