I said there are two ways that “” the book is about how people understood, resisted, and accommodated the origins of manufactured food. But here we are at the next question and I’ll admit the fuller reality of the story is that it’s aimed at the difference between surfaces and interiors. Is appearance reality? Does the surface of a person or a product reflect its true substance? With new foods coming from factories and not just fields, with new packaging and processing, with new sources and more complex distribution networks, it was increasingly difficult to know the veracity of food. Adulteration has been around for millennia, it wasn’t new in the 19th century, but the combination of cultural (trusting people) and environmental challenges (trusting sources and processes) stepped up angst and governmental responses.The history of science, and chemistry in particular, is threaded throughout the book, while taking center stage in the last part. People thought science and industry were the cause of but possibly the solution to worries over food health and identity.Such questions about science and technology’s complicated political role followed from most of the work I’ve done over the past fifteen years. My first book, Notes from the Ground, had examined the cultural and environmental foundations of agricultural science in the early American Republic. That book ended in the 1860s with the arrival of the USDA, where the new sciences of agriculture helped promote new fertilizers and ways of working the land. Fertilizers were one of the first things to have labels on them, showing what you were getting if you bought it from a supplier instead of just applying it from your cows or other sources of soil amendments (like limestone, for example). When I went to find out how that worked—who was certifying these products, who was making them, where was there controversy—the story led me to a fuller exploration of foods rather than farms, of products rather than processes.My professional path, then, brought me to fill in the rest of the nineteenth century. In so doing, I came to understand that the breadth and complexity of these pure food crusades were really about bigger issues of cultural angst amidst rapidly changing demographics and politics. In that story, science was meant to cut through surfaces to reveal the truth inside.