The Doctor's Visit

“The old doctor felt my pulse, evidently thinking of something else the while. ‘Good, good for there,’ he mumbled, and then with a certain eagerness asked me whether I would let him measure my head. Rather surprised, I said Yes, when he produced a thing like calipers and got the dimensions back and front and every way, taking notes carefully. He was an unshaven little man in a threadbare coat like a gaberdine, with his feet in slippers, and I thought him a harmless fool. ‘I always ask leave, in the interests of science, to measure the crania of those going out there,’ he said. ‘And when they come back, too?’ I asked. ‘Oh, I never see them,’ he remarked; ‘and, moreover, the changes take place inside, you know.’ He smiled, as if at some quiet joke. ‘So you are going out there. Famous. Interesting, too.’ He gave me a searching glance, and made another note. ‘Ever any madness in your family?’ he asked, in a matter-of-fact tone. I felt very annoyed. ‘Is that question in the interests of science, too?’ ‘It would be,’ he said, without taking notice of my irritation, ‘interesting for science to watch the mental changes of individuals, on the spot, but...’ ‘Are you an alienist?’ I interrupted. ‘Every doctor should be—a little,’ answered that original, imperturbably. ‘I have a little theory which you messieurs who go out there must help me to prove. This is my share in the advantages my country shall reap from the possession of such a magnificent dependency. The mere wealth I leave to others. Pardon my questions, but you are the first Englishman coming under my observation...’ I hastened to assure him I was not in the least typical. ‘If I were,’ said I, ‘I wouldn’t be talking like this with you.’" (Page 75)


This passage occurs when Marlow visits the doctor before leaving to go to Africa. He must visit the doctor to make sure he is healthy before leaving the country, however, this visit is somewhat unique. Through this passage, the reader learns a lot about Marlow and about how many people perceive African and its inhabitants.
This passage starts off by Marlow beginning to explain his appointment with the doctor. He immediately begins by mentioning that the doctor was "evidently thinking of something else" while completing completing the cursory and typical tasks within any doctors appointment. It is clear that the doctor was mentally distracted while caring for his patient. Marlow proceeds to mention how the doctor asked him if he could measure his head. This is not a typical question for a doctor to ask someone that is just leaving the country. The doctor then proceeded to state that "the changes take place inside," signifying that he believes those that leave the country and go to Africa return home with a changed mind. It seems like the doctor wants to measure Marlow's head to see if the growth and changes in the brain are actually measurable.
The doctor then proceeds on by asking Marlow if he had any history of madness in his family, for scientific purposes of course. When Marlow gets defensive and inquisitive in response, the doctor explains that every doctor is interested in this type of study and a psychological study of his brain would be fascinating. He also tells Marlow that the world would benefit from his findings if these studies worked out well. It became clear that the doctor viewed Marlow as an experimental specimen that he could study and follow for his benefit. 
This passage shows that Marlow was viewed as an experimental person traveling to Africa rather than a normal person. It also demonstrates that Africa was an unknown and exotic land to most people during this time and life there was very mysterious to them. Overall, it demonstrates the great social divide between people from different countries and cultures as well. This passage does a good job of foreshadowing what is to come in the story.