Here is a medical quote about the infant that is so prominently flying
out of its mother's arms:
 
   "The facial appearance of the child is worthy of note.    The eyes
have a shorter than normal palprebal fissure, resulting in relatively
round, "Orphan Annie" eyes.  These are one of features of maternal
alcohol on fetal morphogenesis, described by Jones et al as part of the
fetal alcohol syndrome.
   Short palprebal fissures are not depicted by Hogarth in infants and
young children in his other engravings." (Rodin AE, Infants and gin mania
in 18th-century London, Journal of the American Medical Association,
245:1237-1239, 1981)
 
Also, the guy in the wheelbarrow intrigues me.  He might be suffering
from Wernicke's syndrome, which includes burning of soles of the feet and
poor balance due to the vitamin B-1 deficiency that occurs from a diet
based primarily on ethanol.  But Wernicke described this syndrome (using
alcoholics as case examples) more than a century after Hogarth printed
Gin Lane....