The grapes from which port-wine is made are all grown within the narrow compass of a mountain-valley about twenty-seven miles long by five or six wide, where the conditions of soil and climate most favorable to wine-culture--including a large degree of both heat and cold--are found in perfection. Owing to its elevation the frosts in this district are tolerably severe, while in summer the sun looks steadily down with his hot glance into the valley till its vine-clad sides are permeated by heat. The grapes ripened there are of peculiar richness and strength. The trade is all in the hands of a certain number of English merchants at Oporto, who buy the grapes as they hang of the native farmers and have the wine made under their own supervision. The wine-making is conducted in much the same manner as in other countries, a certain quantity of spirits being added to arrest decay and ensure its preservation. All wine has passed through the first stage of decay, fermentation, and is liable at any time to continue the course. It may be made with little or no alcohol if it is to be drunk within the year: to ensure a longer lease of life some antiseptic is necessary. Port is, from its richness, peculiarly liable to decay, and will stand fortification better than sherry, which being a light wine is less in need of it and more apt to be over-fortified. The area in which port is produced being so small, there can be no material difference in the produce of different vineyards, but some slight superiorities of soil or aspect have given the Vesuvio, the Raida and a few other wines a special reputation. The history of port is a somewhat curious one. It is associated closely with the old English gentleman of a bygone generation, a staunch and bigoted being who despised French wines as he abhorred the French nation, and agreed with Doctor Johnson that claret was for boys, port for men. The vintage of 1820 was a remarkable one in Portugal. The port made in that season was of a peculiar strength and sweetness, in color nearly black. The old English gentleman would acknowledge no other as genuine, and, as Nature positively refused to repeat the experiment, the practice of dyeing port with dried elderberries and increasing the infusion of brandy to impart strength and flavor was resorted to. It was successful for some time, but after a while the secret oozed out, and the public began to receive the garnet-hued liquid again into favor, and to find, with Douglas Jerrold, that it preferred the old port to the _elder_. The elderberry is not sufficiently common in Portugal to make the continuation of this process popular with wine-makers. At present port is tolerably free from adulteration, though its casks and those of an inferior red wine of Spain after voyaging to England sometimes find their contents a little mixed.