In what ways is the visit to newgate Prison by Wemmick and Pip and indictment by Dickens on the penal system of the day

Chapter XXXII of Great Expectations finds
Pip taking a tour of the infamous Newgate Prison.  With the personal memory of debtors' prison in
which his father was incarcerated, Charles Dickens paints a portrayal of the prison as a place
that is sorely neglected.  The food is poor and the men must buy their beer.  As Wemmick walks
among the various prisoners, he talks to them, but cautions them that he is only a subordinate
and they must talk to "the principals."  While he traverses the grounds, Wemmick shakes no one's
hand, a sign of the fear of disease, especially cholera.

The ironic
use of similes, comparing the prisoners to the plants in a garden that are replaced with others
after they die, Dickens illustrates the small value placed on the life of the individual in
prison, a dismal and tragic place where people are discarded.