their vigor, and on publishing my own ideas, have never been accused of being a servile disciple or of swearing 'in verba magistri'. From these studies I passed to the elements of geometry, for I never went further, forcing my weak memory to retain them by going the same ground a hundred and a hundred times over. I did not admire Euclid, who rather seeks a chain of demonstration than a connection of ideas: I preferred the geometry of Father Lama, who from that time became one of my favorite authors, and whose works I yet read with pleasure. Algebra followed, and Father Lama was still my guide: when I made some progress, I perused Father Reynaud's Science of Calculation, and then his Analysis Demonstrated; but I never went far enough thoroughly to understand the application of algebra to geometry. I was not pleased with this method of performing operations by rule without knowing what I was about: resolving geometrical problems by the help of equations seemed like playing a tune by turning round a handle. The first time I found by calculation that the square of a binocular figure was composed of the square of each of its parts, and double the product of one by the other; though convinced that my multiplication was right, I could not be satisfied till I had made and examined the figure: not but I admire algebra when applied to abstract quantities, but when used to demonstrate dimensions, I wished to see the operation, and unless explained by lines, could not rightly comprehend it. After this came Latin: it was my most painful study, and in which I never made great progress. I began by Port-Royal's Rudiments, but without success; I lost myself in a crowd of rules; and in studying the last forgot all that preceded it. A study of words is not calculated for a man without memory, and it was principally an endeavor to make my memory more retentive, that urged me obstinately to persist in this study, which at length I was obliged to relinquish. As I understood enough to read an easy author by the aid of a dictionary, I followed that method, and found it succeed tolerably well. I likewise applied myself to translation, not by writing, but mentally, and by exercise and perseverance attained to read Latin authors easily, but have never been able to speak or write that language, which has frequently embarrassed me when I have found myself (I know not by what means) enrolled among men of letters.