Final answer:
The question seeks historical data on food-borne botulism outbreaks from 1899 to 1997, specifically the number of outbreaks by food source, which would show the impact of sterilization and canning procedures on the incidence of botulism.
Step-by-step explanation:
The number of food-borne botulism outbreaks by food source from 1899 to 1997 reflects historical instances of a serious foodborne illness caused by the anaerobic bacterium Clostridium botulinum. This bacterium could thrive in the anaerobic environment of non-acidic canned foods, homemade pickles, and processed meats and sausages. Advances in sterilization and canning procedures have since significantly reduced the incidence of botulism.
However, tracking specific numbers of outbreaks by food sources during that period would require access to historical epidemiological data that is not provided here. Notably, newer data from FoodNet from 2000 to 2007 indicates a broader perspective on foodborne illnesses, illustrating that the causes and scale of food production related to these illnesses have evolved over time.