In 1736 I lost one of my Sons, a fine Boy of 4 Years old, by the Smallpox taken in the common way. I long regretted bitterly and still regret that I had not given it to him by Inoculation. This I mention for the Sake of Parents who omit that Operation on the Supposition that they should never forgive themselves if a Child died under it; my Example showing that the Regret may be the same either way, and that therefore the safer should be chosen.
On Immunization, Part III, p. 83 - The Autobiography (1817)