Our troop carries a fairly large commercial first aid kit in our troop trailer. It is kept restocked by one of our assistant Scoutmasters who is a firefighter paramedic. Quite honestly the only thing used from the kit is adhesive bandages of one size or another. We might have also used some antibiotic cream.

Each Scout who is of Second Class is "supposed" to be carrying a personal first aid kit that was put together as one of the second class rank requirements. Some probably actually carry them, but many probably don't. That would be a great inspection item for one of our next campouts.

That is not to say that nasties don't happen. A few years back my son - of all the boys in the pack - broke his collarbone while at a council-wide event event at the summer camp property. That required a ton of elastic bandages to immobilize his arm until the ambulance arrived for transport to the local hospital (a fun night that was).

At this year's summer camp a boy in the next camp site over sliced a good length of skin off the outside of his thumb. I guess it bleed like crazy. Lots of gauze needed while on the way to the very same hospital.

So, the list should include at the very least:
Protective gloves (latex or other)
Eye protection
Adhesive bandages of all sizes, and lots of them
Large gauze pads, for bigger cuts
Adhesive tape
Elastic bandages, and lots of them
Gauze wrap
Triangular bandages
Scissors
GOOD Tweezers
Soap
Antibiotic ointment
CPR barrier
Fever Thermometer
Ice packs
Diarrhea medicine
Antihistamine