EDIT
He looks deep into the shaft, scrutinizing it with his discerning eye. All he sees is limestone and the occasional drip of water. PLOOP Probably a result of the hot draft blowing in. Condensation or melting ice perhaps. PLOOP As a precaution, Blink tosses a rock into the narrow shaft. It bounces off some of the limestone formations and settles in a shallow pool of water. No razors or tentacle monsters reveal themselves. PLOOP The rock is fine. The passage looks fine. He decides that it is probably safe to shadow jaunt over there.
Spoiler
I did read the stone thing, I just failed to comment on it because it would have no effect. Adding it in makes for a more interesting post though.
I'm afraid I can think of no way to cut you slack in this case. You failed the spot check, the stone is unaffected, and you transported directly on to source of the acid. I usually like to give better hints that an area is trapped/hazardous, but given the deathy type nature of this adventure and the plenitude of bones, I can't say I feel all that bad. You'll live.
END EDIT
Blink pops out of existence here and rematerialized there. An instant later he howls in pain when his hands and toes begin to burn and the scales and flesh melt away. GGAAAAAAAAAAHHHHHHH!!!!! Any place he touches the ceiling disintegrates with a foul smelling hissss Blink drops from the ceiling, not because he loosened his grip, but because the flesh that was attached to the rocky ceiling was left behind. He falls a foot onto his back. AAAAAAHHHHHHHHHH!!!!! Drips of condensed acid fall from the roof to his shin, his nose, his belly. The sizzles and corrode deep into his flesh AAAAHHHHHHHHHH!!!!!
Spoiler(4d6)[17] Acid damage. Assuming you get out of there alive there will be more damage next round too. If you don't get out of there you will continue to take 4d6/round until you do.