How does Jekyll explain the sense of "deformity and decay" Hyde seems to give off? What is Jekylls explanation for people's strong reaction to hyde?

Jekyll quite liked the look of his Hyde, "had left on that body an imprint of deformity and decay. And yet when I looked upon that ugly idol in the glass, I was conscious of no repugnance, rather of a leap of welcome." He was, however, aware that ,

"all human beings, as we meet them, are commingled out of good and evil: and Edward Hyde, alone in the ranks of mankind, was pure evil."