The House under the Sea by Max Pemberton

We had no notion that the doctor had come by any serious hurt, and when he fell in a dead faint we stood as men struck by an unseen hand. Light we still had, for the rolling lantern continued to burn; but the wits of us, save the wits of one, were completely gone, and three sillier fellows never gaped about an ailing man. Dolly Venn alone -- trained ashore to aid the wounded -- kept his head through the trouble and made use of his learning. The half of a minute was not to be counted before he had bared an ugly wound and showed us, not only a sucker still adhering to the crimson flesh, but a great, gaping cut which the doctor's own knife had made when he severed the fish's tentacle.

"You, Seth Barker, hold up that lantern," says he to the carpenter, as bold as brass and as ready as a crack physician at a guinea a peep; "give me some linen, one of you -- and please be quick about it. I'll trouble you for a knife, Mister Peter, and a slice of your shirt, if you don't mind!"