Final answer:
An inference about Dr. Mesmer is that he might have been an earnest if misguided practitioner or a clever impresario, and descriptive details of his practice and the investigation into it by empirical minds like Benjamin Franklin contribute to this inference.
Step-by-step explanation:
Part A: An inference that can be made about Dr. Mesmer is that he could have been a misunderstood pioneer or perhaps someone exploiting misconceptions depending on one's interpretation of the available historical evidence. Part B: To support this inference, it is best to look at descriptions of Dr. Mesmer's practices and how they were perceived by contemporaries, such as Benjamin Franklin, who investigated the phenomena of electricity and could discern between scientific principles and mere spectacle.
For example, Franklin's work in understanding electricity through experiments with the Leyden jar and his demonstration that lightning was akin to static electricity suggest a methodical and empirical approach to scientific inquiry belonging to the Enlightenment ideals. These details contrast with the superstitious and less empirical nature implied in the reference to Dr. Mesmer's mental condition and the impressions he held about his dwelling. Thus, a supported inference could be that Mesmer was either deeply influenced by his own beliefs to the point of self-deception or strategically used these notions to influence others.
Furthermore, the narrative provided in portraits, such as Benjamin Franklin Drawing Electricity from the Sky, and the recounting of scientific progress through inductive and deductive reasoning, underscore the period's value on evidence-based conclusions over more speculative or superstitious assertions.