This work surveys methods and industries that reclaim and convert waste into valuable materials, arguing that large-scale recovery can yield significant commercial and national benefits. It outlines economic causes of waste and compares practices, including foreign approaches, municipal salvage, military and slaughterhouse refuse, and industrial by-products such as fats, bones, paper, oils, nitrogenous matter, and coal residues. Case studies and technologies—magnetic salvage, waste-derived fertilizers, sewage sludge processing, and construction materials—illustrate practical recovery techniques and inventions. The book concludes by considering remaining opportunities and future development for turning refuse into revenue and conserving raw resources.