DEAR SIR,--A journey into the southern parts of France and northern of Italy must apologize to you for the length of time elapsed since my last, and for the delay of acknowledging the receipt of your favors of November 8 and December 9, 1786, and April 14, 1787. Your two phials of essence de l'Orient arrived during that interval, and got separated from the letters which accompanied them, so that I could not be sure which was your first preparation, and which was your second. But I suppose, from some circumstances, that the small phial was the first, and the larger one the second. This was entirely spoiled, so that nothing was distinguishable from it. The matter in the small phial was also too much spoiled for use; but the pearl merchant, from whom I got my details, said he could judge, from what remained, that it had been very good; that you had a very considerable knowledge in the manner of preparing, but that there was still one thing wanting which made the secret of the art; that this is not only a secret of the art, but of every individual workman who will not communicate to his fellows, believing his own method the best; that of ten different workmen, all will practice different operations, and only one of the ten be the right one; that the secret consists only in preparing the fish, all the other parts of the process in the pearl manufactory being known. That experience has proved it to be absolutely impossible for the matter to cross the sea without being spoiled; but that if you will send some in the best state you can, he will make pearls of it, and send to you that you may judge of them yourself. He says the only possible method of making anything of it would be for a workman to go over. He would not engage in this, nor would he buy, because he says it is their custom to have contracts for nine years' supply from the fishermen, and that his contract furnishes him with as much as he can sell in the present declining state of the pearl trade; that they have been long getting out of fashion, polite people not wearing them at all, and the poor not able to give a price; that their calling is, in fact, annihilating; that when he renews his contract he shall be obliged to reduce the price he pays twenty-five per cent.; that the matter sells from five to eight livres the French pound, but most generally at six livres. He showed me a necklace of twelve strands, which used to sell at ten livres, and now sells for two and a half. He observed that the length of time the matter will keep depends on the strength of the spirit of wine. The result is, then, that you must send me a sample of your very best, and write what you would propose after weighing these circumstances. The leg and feathers of the bird are also arrived; but the comb, which you mention as annexed to the foot, has totally disappeared. I suppose this is the effect of its drying. I have not yet had an opportunity of giving it to Monsieur de Buffon, but expect to do it soon.