Consequences of Improper Canning
All food should be inspected before being prepared for the table. Canned food is no exception to this rule. If there is any evidence of spoilage, the food should be discarded and nonacid vegetables and meats should be burned.
--Stanley, L. & Stienbarger, M. C. (1936). Home canning of fruits, vegetables, and meats. United States Department of Agriculture: Farmers' Bulletin, 1762. Retrieved from https://archive.org/details/CAT87205286