My sleepless nights, my incessant toil, and, above all, the feverish agitations resulting from all the emotions of such an arduous undertaking, had undermined my health. A brain-fever attacked me, and though I recovered from it, it was only to pass five long years in listlessness and vacuity. My mind seemed quite gone: I felt no passion, no love, no interest, even in the arts I had so delighted in: conjuring and mechanism only existed for me in the shape of recollections. But this illness, which had mastered the faculty of Paris, could not resist the refreshing air of the country, where I retired for six months, and when I returned to Paris, I was a new man. With what joy I saw again my beloved tools! With what ardor I reassumed my work! for I had to regain not only the lost time, but also the enormous expenses incurred by my long illness. My modest fortune was for the moment sensibly diminished, but on this point I was case-hardened; for would not my future performances fill up all these losses, and insure me a handsome fortune? Thus I discounted an uncertain future; but, after all, do not all inventors like to convert their schemes into ingots? Perhaps, too, I unconsciously yielded to the influence of one of my friends, an extraordinary projector, whom mistakes and deceptions never hindered forming fresh schemes. Our manner of calculating the future had considerable affinity. But I must do him this justice: however high my estimate might be, he was far superior to me in that respect. Here is an instance to judge by. One day this friend called upon me, and showing me an inkstand of his invention, which combined the double merit of being safe from upset, and of always keeping the ink at the same level, said, “At last, my lad, I have hit it; this invention will make a revolution in the writing world, and allow me to walk about like a gentleman, with a hundred thousand francs a year--at the very lowest, understand me. But you can judge for yourself, if you follow my calculations closely. You know, there are thirty-six millions of inhabitants in France?” I nodded an affirmative. “Starting on this basis, I do not think I err if I assume that at least one-half can write, eh? or, say we take one-third, or, to be still more sure, the round sum of ten millions. Now, I hope I shall not be charged with exaggeration, if, out of these ten millions, I take one-tenth, or a million, as the number of those looking after what may be useful to them.” And my friend stopped here and looked at me, as much as to say, “Am I not reasonable in my estimates?” “We have, then, in France one million men capable of appreciating the benefits of my inkstand. Well, of this number how many will you allow who, during the first year, hear of my inkstand, and consequently will purchase it?” “Well,” I replied, “I confess to a difficulty in giving you an exact answer.”