here'sw what it says:
You usually have between six and 12 hours to have the finger reattached, so acting fast is essential. As soon as an accident occurs, you should:
Gather all parts of the severed finger, no matter how small. The surgeon may need them.
Put the finger and any parts on ice and wrap it in plastic wrap.
Place the finger in a jar or cup with lid.
Do not put it in water, as this will cause it to shrivel.
Call an ambulance and/or get to the emergency room as quickly as possible.
"Replanting" surgeries can be very successful if these steps are followed (as long as there is not extensive damage to the muscles). In fact, a 62-year-old woman recently had six of her fingers sliced off in a work accident.