A stone bridge, built by Napoleon, however, crosses the river at Aiguillon, which stands at the confluence of the Lot and Garonne, and is famous for its castle, built by the Duke d'Aiguillon--that minister who, protected by Mde. du Barry, gave his aid towards preparing the downfal of France, undermined by the acts of a series of worthless characters, in every department of the state, from the monarch downwards. Marie Antoinette held him in especial odium, and he was exiled, by her desire, to his gorgeous château on the Lot, where he was, in fact, a prisoner, not being allowed to sleep out of it; on one occasion, when he visited Agen for two days, word was sent to him that it was expected he should not prolong his stay. The castle, in his time, was a Versailles in miniature, and was not entirely finished at the Revolution. An ancient Roman tower, of which a few walls only now remain, on the route to Agen, was once a conspicuous object from the river: it was called _La Tourrasse_, ("_enormous tower_" in _patois_), and many discoveries prove the importance of this place in the time of the Romans. The Baïse is the next river that falls into the Garonne, following whose banks towards Nerac is Barbaste and its old château, of which Henri Quatre was fond of calling himself _The Miller_, which title, on one occasion, stood him in good stead when a great danger threatened him; a soldier of the opposite party, who came from this part of the country where the prince was always beloved, could not resolve to see the destruction which awaited him if he had advanced a step towards a mine which was just on the point of blowing up. At the critical instant, he called out, in _patois_, which none but Henry understood, "Moulié dé Barbaste, pren garde a la gatte qué bay gatoua:"--'Millar of Barbaste, beware of the cat' (_gatte_ means, indifferently, _cat_ or _mine_) 'which is going to kitten' (_gatoua_ has the meaning of _blowing up_, as well.) Henry drew back in time, just as the mine exploded. Thanks, therefore, to his readiness, and the expressive nature of the Gascon _patois_, the hero was, for that time, saved; he took care not to lose sight of his deliverer, and, on a future occasion, rewarded him amply for the service he had rendered. The little port of St. Marie, well known as a safe harbour to the fishermen of the Garonne, once formed part, with the town, of the possessions of Raymond, the last Count of Toulouse; who, after a series of persecutions from the Pope and the King of France, (St. Louis,) to induce him to give up the protection of the Albigenses, was permitted to retain this portion, only on condition of destroying the fortifications of the strong castle which existed there. Guy, Viscount de Cavaillon, his friend and fellow troubadour, on one occasion addressed to him the following lines, to which he returned the answer subjoined; but, nevertheless, was obliged to submit to the power of the Church, like the rest of the world: