How does Michel Foucault use imagery in The History of Sexuality: An Introduction?

Imagery:

"But twilight soon fell upon this bright day, followed by the monotonous nights of the Victorian bourgeoisie. Sexuality was carefully confined; it moved into the home. The conjugal family took custody of it and absorbed it into the serious function of reproduction. On the subject of sex, silence became the rule."

"Although not without delay and equivocation, the natural laws of matrimony and the immanent rules of sexuality began to be recorded on two separate registers. There emerged a world of perversion which partook of that of legal or moral infraction, yet was not simply a variety of the latter. An entire sub-race race was born, different - despite certain kinship ties - from the libertines of the past. From the end of the eighteenth century to our own, they circulated through the pores of society; they were always hounded, but not always by laws; were often locked up, but not always in prison; were sick perhaps, but scandalous, dangerous victims, prey to a strange evil that also bore the name of vice and sometimes crime. They were children beyond their servants and educators, cruel or maniacal husbands, solitary collectors, ramblers with bizarre impulses; they haunted the houses of correction, the penal colonies, the tribunals, and the asylums; they carried their infamy to the doctors and their sickness to the judges. This was the numberless family of perverts who were on friendly terms with delinquents and akin to madmen. In the course of the century they successively bore the stamp of 'moral folly,' 'genital neurosis,' 'aberration of the genetic instinct,' 'degenerescence,' or 'physical imbalance."'