The passage discusses the history and methods of food drying. It notes that ancient peoples like Native Americans and Scandinavians discovered that removing moisture from food through sun drying helped preserve it. It then explains that all foods contain high percentages of water, and removing this water inhibits bacterial growth that causes spoilage. The passage describes traditional sun drying methods and also modern mechanical drying processes using hot air. It concludes by noting the advantages of dried foods in terms of storage, weight, and ease of cooking.