Answer:
The print shop apprentice
Step-by-step explanation:
The print shop apprentice is the character who represents the idea that "The Yellow Fever always begins in the lowest part of a populous mercantile town near the water, and continues there, without affecting the higher parts". The print shop apprentice observes that the aedes mosquito responsible for transmitting the yellow fever virus breeds on stagnant water found in lowest part of a populous mercantile and has the tendency to keep on spreading at a fast rate without affecting the higher part. This is as a result of poor environmental sanitation.