This essay is a study of the “Project for the establishment of a war and hunting gunpowder manufactory in the United States,” written by Irénée Du Pont de Nemours in 1800, in order to raise funds from potential investors for what was to become the DuPont Corporation. It shows that the “Project” is best understood as a demonstration device akin to those used by natural philosophers at the time. This investment proposal relied on demonstration techniques similar to those of the report of an experiment, textually gathering a crowd of virtual witnesses to address their objections, submitting the proposed manufactory to a number of manipulations to assess its reactions under various circumstances, and relying on a specific experimental device—a profit-and-loss account—that made it possible to produce compelling quantitative results. The essay shows the originality of these techniques at a time when profit-and-loss calculations were uncommon in business practice. It explains that these calculations were intended to ameliorate the entrepreneur’s problematic credit situation, which required a specific demonstrative effort, and points to scientific demonstration practices in Physiocratic political economy, and in Lavoisier’s chemistry, as likely influences.