During this interval of time much of my matter has escaped my memory, or been wrested from me. Elementary books on chemistry or materia medica have been put into the hands of every body, and things I expected to teach for the first time, have become popular. For instance, I had devoted many pages to the chemistry of the pot-au-feu, the substance of which is found in many books recently published. Consequently, I had to revise this part of my book, and have so condensed it that it is reduced to a few elementary principles, to theories which cannot be too widely propagated, and to sundry observations, the fruits of a long experience, which I trust will be new to the majority of my readers. Section I. POT-AU-FEU, POTAGE, ETC. Pot-au-feu is a piece of beef, intended to be cooked in boiling water, slightly salted so as to extract all the soluble parts. Bouillon is the fluid which remains after the operation. Bouilli is the flesh after it has undergone the operation. Water dissolves at first a portion of the osmazome; then the albumen coagulates at 50 degrees Reaumur, and forms the foam we see. The rest of the osmazome, with the extractive part of juice, and finally a portion of the wrapping of the fibres detached by the continuity of ebullition. To have good bouillon, the water must be heated slowly, and the ebullition must be scarcely perceptible, so that the various particles necessarily dissolved, may unite ultimately and without trouble. It is the custom to add to bouillon, vegetable or roots, to enhance the taste, and bread or pates to make it more nourishing. Then it is what is called potage. Potage is a healthy food, very nourishing, and suits every body; it pleases the stomach and prepares it for reception and digestion. Persons threatened with obesity should take bouillon alone. All agree that no where is potage made so well as in France, and in my travels I have been able to confirm this assertion. Potage is the basis of French national diet, and the experience of centuries has perfected it. Section II. BOUILLI. Bouilli is a healthful food, which satisfies hunger readily, is easily digested, but which when eaten alone restores strength to a very small degree, because in ebullition the meat has lost much of its animalizable juices. We include in four categories the persons who eat bouilli. 1. Men of routine, who eat it because their fathers did, and who, following this practice implicitly, expect to be imitated by their children. 2. Impatient men, who, abhorring inactivity at the table, have contracted the habit of attacking at once whatever is placed before them. 3. The inattentive, who eat whatever is put before them, and look upon their meals as a labor they have to undergo. All that will sustain them they put on the same level, and sit at the table as the oyster does in his bed.