Davy seriously injured himself in a laboratory accident with nitrogen trichloride. French chemist Pierre Louis Dulong had first prepared this compound in 1811, and had lost two fingers and an eye in two separate explosions with it. In a letter to John Children, on 16 November 1812, Davy wrote: "It must be used with great caution. It is not safe to experiment upon a globule larger than a pins head. I have been severely wounded by a piece scarcely bigger. My sight, however, I am informed, will not be injured". Davys accident induced him to hire Michael Faraday as a co-worker, particularly for assistance with handwriting and record keeping. He had recovered from his injuries by April 1813.