Letter, from Augustus De Morgan to Sir John Herschel, dated at 91 Adelaide Road Autograph letter signed by sender. Has managed to write out the song and insert the Blaise Pascal verse. Gave some advice to an Assurance Office yesterday, so he must be improving. Illness in his family this season has taken the form of great prostration. Gives curious confirmation of Isaac Newton's lack of knowledge of French. Blaise Pascal affair is growing into an epic. 23 October 1867