Do you drip... into your mouth?

[Angela]

You're welcome

[Nick O'Teen]

This gave me an idea. What happens if your batteries are all dead but you have a dropper and plenty of juice. Would it hurt to drip a drop or two of 16mg or 24mg right under your tongue and let it absorb?

It wouldn't cause any overdose problems, but it tastes pretty meh, and might cause soreness or mouth ulcers. The top of your tongue is probably a wiser choice, since it's rather less sensitive. I've tasted a couple of mine (only a drop at a time,) and I have to confess I'd rather have a pinch of snuff if my minipipe failed me. If I didn't have any snuff on me, then I'd probably try it again rather than go without for more than a few hours, but it would be pretty much a last resort.

I know nicotine is toxic, and after reading through a couple of posts on here, I have seen that 40+mg of nicotine may be fatal if it is all absorbed in a short period of time.

40mg is just about at the very bottom end of the lethal range for a small non-smoker. And even then you'd need to drink more than 1ml of the strongest juice available to ingest that much (and half a teaspoonful of 16mg!) At 20 drops per ml (roughly,) that's not going to be a problem with accidental cart leakage, or a couple of drops on your tongue.
As with so many things in life, it's all a matter of dosage and common sense. I mean, if we had more sense, we probably wouldn't have picked up a nicotine addiction in the first place

All this being said, is dripping into your mouth in a pinch ok to do?

I'd have to be fairly desperate, but if I was - yeah, I'd do it again. It didn't cause any irritation to my mouth lining, but YMMV.
Diluting it might be more palatable/less irritating.