Trim off fat and gristle. Cut meat into 1-inch chunks. Remove skin from chicken; leave bone in. Shape hamburger into 1/2-inch thick patties. Pack raw meat into hot, sterilized jars, leaving one-inch headspace. Add 1/2 tsp. Salt or 1 bouillon cube (optional). Add no liquid. Screw on sterilized lids hand tight. Fill canner with 3 inches fresh water. Place jars on rack in canner. Secure cover, but leave petcock open. Heat, letting steam escape for 10 minutes to evacuate air from jars. Then close petcock and process for 1 hour, 15 minutes at 10 lbs. pressure. Remover cooker from heat and allow pressure to release naturally. Cool jars 10 minutes in cooker. Place jars on cloth away from drafts until cool. After 24 hours, test seals by checking that lids are concave and do not pop up and down when pushed with finger. Remove screw bands, label lids with contents and date, and store indefinitely. Before using, check seal, smell contents, and if in doubt, throw it out!