The experiment of second sight always formed the termination of my performance. Each evening I saw unbelievers arrive with all sorts of articles to triumph over a secret which they could not unravel. Before going to see Robert-Houdin's son a council was held, in which an object that must embarrass the father was chosen. Among these were half-effaced antique medals, minerals, books printed in characters of every description (living and dead languages), coats-of-arms, microscopic objects, &c.
But what caused me the greatest difficulty was in finding out the contents of parcels, often tied with a string, or even sealed up. But I had managed to contend successfully against all these attempts to embarrass me. I opened boxes, purses, pocket-books, &c., with great ease, and unnoticed, while appearing to be engaged on something quite different. Were a sealed parcel offered me, I cut a small slit in the paper with the nail of my left thumb, which I always purposely kept very long and sharp, and thus discovered what it contained. One essential condition was excellent sight, and that I possessed to perfection. I owed it originally to my old trade, and practice daily improved it. An equally indispensable necessity was to know the name of every object offered me. It was not enough to say, for instance, "It is a coin;" but my son must give its technical name, its value, the country in which it was current, and the year in which it was struck. Thus, for instance, if an English crown were handed me, my son was expected to state that it was struck in the reign of George IV., and had an intrinsic value of six francs eighteen centimes.
Aided by an excellent memory, we had managed to classify in our heads the name and value of all foreign money. We could also describe a coat-of-arms in heraldic terms. Thus, on the arms of the house of X---- being handed me, my son would reply: "Field gules, with two croziers argent in pale." This knowledge was very useful to us in the _salons_ of the Faubourg Saint Germain, where we were frequently summoned.
I had also learned the characters--though unable to translate a word--of an infinity of languages, such as Chinese, Russian, Turkish, Greek, Hebrew, &c. We knew, too, the names of all surgical instruments, so that a surgical pocket-book, however complicated it might be, could not embarrass us. Lastly, I had a very sufficient knowledge of mineralogy, precious stones, antiquities, and curiosities; but I had at my command every possible resource for acquiring these studies, as one of my dearest and best friends, Aristide le Carpentier, a learned antiquary, and uncle of the talented composer of the same name, had, and still has, a cabinet of antique curiosities, which makes the keepers of the imperial museums fierce with envy. My son and I spent many long days in learning here names and dates, of which we afterwards made a learned display. Le Carpentier taught me many things, and, among others, he described various signs by which to recognise old coins when the die is worn off. Thus, a Trajan, a Tiberius, or a Marcus Aurelius became as familiar to me as a five-franc piece.