Poison or remedy?

Dread and Deluge, she wondered if they were born with those names or if they named themselves as such. Very heavy and hostile names that mirrored their physiques and style. She tilted her head at Dread's dry delivery, the joke flying over her, his fur nearly too dark for her to catch the faint upturn of his lip. "Oh no, I hope your healer doesn't poison their patients!" She replied worried, but she got the joke when Deluge sarcastically added her own joke,

"Oh! Oh, you two!" She tittered and threw her gaze to the ground and off to the right bashfully. It wasn't often she'd miss a joke so blatantly!

So the stuff was used as a fungicide, insecticide, poison, coloring agent, or dye. There were so many uses! How had they come across this information? They might have come here to this strange island just for this stuff and so had this knowledge to guide them, it made sense to Morwenna that way.

She also felt a little tired from the conversation, or was it perhaps the land affecting her? The copper sulfate might be in the air as they dig around and kick up the sands.

"Thank you so much for readily sharing your knowledge with me! I think this stuff is making my paws itch! I'll owe you a favor if we meet again Dread, Deluge." She dipped her head to Dread but offered a wink to Deluge, then she bounded off with a smirk, toward the mainland and hoped to wash off the copper-green sands during her brief swim back.