The greatest obstacle to making the experiment of my system was the fear, in case of its not being received, of losing the time necessary to learn it.  To this I answered, that my notes rendered the ideas so clear, that to learn music by means of the ordinary characters, time would be gained by beginning with mine.  To prove this by experience, I taught music gratis to a young American lady, Mademoiselle des Roulins, with whom M. Roguin had brought me acquainted.  In three months she read every kind of music, by means of my notation, and sung at sight better than I did myself, any piece that was not too difficult.  This success was convincing, but not known; any other person would have filled the journals with the detail, but with some talents for discovering useful things, I never have possessed that of setting them off to advantage.

Thus was my airy castle again overthrown; but this time I was thirty years of age, and in Paris, where it is impossible to live for a trifle.  The resolution I took upon this occasion will astonish none but those by whom the first part of these memoirs has not been read with attention.  I had just made great and fruitless efforts, and was in need of relaxation.  Instead of sinking with despair I gave myself up quietly to my indolence and to the care of Providence; and the better to wait for its assistance with patience, I lay down a frugal plan for the slow expenditure of a few louis, which still remained in my possession, regulating the expense of my supine pleasures without retrenching it; going to the coffee-house but every other day, and to the theatre but twice a week.  With respect to the expenses of girls of easy virtue, I had no retrenchment to make; never having in the whole course of my life applied so much as a farthing to that use except once, of which I shall soon have occasion to speak.  The security, voluptuousness, and confidence with which I gave myself up to this indolent and solitary life, which I had not the means of continuing for three months, is one of the singularities of my life, and the oddities of my disposition.  The extreme desire I had, the public should think of me was precisely what discouraged me from showing myself; and the necessity of paying visits rendered them to such a degree insupportable, that I ceased visiting the academicians and other men of letters, with whom I had cultivated an acquaintance.  Marivaux, the Abbe Malby, and Fontenelle, were almost the only persons whom I sometimes went to see.  To the first I showed my comedy of Narcissus.  He was pleased with it, and had the goodness to make in it some improvements.  Diderot, younger than these, was much about my own age.  He was fond of music, and knew it theoretically; we conversed together, and he communicated to me some of his literary projects.  This soon formed betwixt us a more intimate connection, which lasted fifteen years, and which probably would still exist were not I, unfortunately, and by his own fault, of the same profession with himself.