^{page 361 note} * My paper having been drawn up previously to the publication of Professor De Morgan's article in the Assurance Magazine for July, 1859 (which is the only one I hare seen on the subject), the enunciation of the property in question is given as nets. In a letter to the Editor, which accompanied my manuscript a few days after the publication of the Number for July, 1859, I referred to Mr. De Morgan's prior discovery, bat, by an oversight, omitted to insert a similar reference in the paper itself.

^{page 362 note} * The characters correspond with those used in my paper of January, 1860.