JONATHAN SWIFT IN 1729 MENTIONS THE WEIGHT OF AN INFANT AT BIRTH AND AT A YEAR OF AGE

I believe the first mention in English of the weight of an infant at birth and at a year of age is found in Jonathan Swift's (1667-1745) biting satire A Modest Proposal for Preventing the Children of Poor People from being a Burden to their Parents or the Country (1729). Swift wrote: I have reckoned upon a medium that a child just born will weigh 12 pounds, and in a solar year, if tolerably nursed, will increase to 28 pounds.1 How did Swift arrive at such an erroneously high figure for the birth weight of the new-born infant? A natural assumption might be that he made it up by pairing Hibernian hyperbole with literary license. But I am convinced this is not so because in Marsh's Library, attached to St. Patrick's Cathedral in Dublin, where Swift actually wrote many of his satires, including his Modest Proposal, he had access to and read carefully the fourth edition (1694) of Mauriceau's (1637-1709) Traité des Maladies des Femmes Grosses. Swift's penned marginalia in Mauriceau's text convince me that this book was the source of the erroneous birthweight mentioned in the above quotation. Mauriceau claimed that an infant weighed about 12 pounds at birth.2 Swift had every reason to accept this statistic because it came from a text written by the foremost obstetrician of the time.