Demonville.—A Frenchman's Christian name is his own secret, unless there be two of the surname. M. Demonville is a very good instance of the difference between a French and English discoverer. In England there is a public to listen to discoveries in mathematical subjects made without mathematics: a public which will hear, and wonder, and think it possible that the pretensions of the discoverer have some foundation. The unnoticed man may possibly be right: and the old country-town reputation which I once heard of, attaching to a man who “had written a book about the signs of the zodiac which all the philosophers in London could not answer,” is fame as far it goes. Accordingly, we have plenty of discoverers, who, even in astronomy, pronounce the learned in error because of mathematics.