"[N]ear half the children that are born and bred in London die under two years of age. ...[T]he constant and unremitting Poison is communicated by the foul Air, which, as the Town still grows larger, has made regular and steady advances in its fatal influence. ...[W]e are accustomed to read with great composure of the deaths of thosands of infants, suffocated every Year by Smoke and Stenches which good policy might in a great measure remove."