At the beginning of this Chapter, when Utterson goes to visit Dr. Jekyll, he is admitted to Jekyll's laboratory for the first time. In fact, he was not even aware of the existence of this part of the property (and the three "dusty windows barred with iron" will later be the windows where Utterson and Enfield will see Dr. Jekyll sitting, in Chapter 7). Note that when Utterson meets Dr. Jekyll here, he is aware that an immense change has taken place in the doctor: Dr. Jekyll looked "deadly sick." He did not rise to meet his visitor, but held out a cold hand and "bade him welcome in a changed voice." Dr. Jekyll's sickness, of course, symbolically represents his sick conscience that is shocked that such a horrible murder could take place, for he, of course, knows that he (or a part of him) is responsible for the crime.
It is likewise ironic that when Utterson asks Jekyll directly, "You have not been mad enough to hide this fellow," the pun on hide is challenging, because the reason for the creation of Hyde was so that Dr. Jekyll could indeed hide his own debaucheries behind Hyde and still live his own respectable life as Dr. Jekyll. And when the doctor assures Utterson that "I swear to God I will never set eyes on him again. I bind my honor to you that I am done with him in this world," we assume (along with Utterson) that Dr. Jekyll is speaking the truth; however, this is an oath that will be impossible to keep because Hyde has too much of a grasp on Dr. Jekyll, who will indeed, as in the next Chapter, hide Hyde for awhile, but eventually Hyde will emerge on his own terms.
When Utterson again points out to Dr. Jekyll the possibility that he and his name would be dragged through a trial if Hyde is ever caught, Dr. Jekyll again insists that "I am quite done with him." Again, the point is that since his early youth, Dr. Jekyll has tried to outwardly live an exemplary life, and his creation of Hyde was done out of scientific curiosity and also so that Dr. Jekyll could participate in debaucheries without danger of detection; therefore, now, the fear of scandal makes the doctor resolve to never see Hyde again. As Dr. Jekyll says, "I was thinking of my own character, which this hateful business has rather exposed." And too, he has always feared that his distinguished reputation would be stained by his secret, dubious activities.
