Many wines acquire with age a more or less bitter taste, sometimes to a degree which renders them unfit for consumption. Red wines, without exception, are subject to this disease. It attacks by preference wines of the best growth, and particularly the finest wines of the Côte-d'Or. It is once more a little filamented fungus which works the change; and not only does it cause in the wine a bitterness which little by little deprives it of all its better qualities, but it forms in the bottles a deposit which never adheres to the glass, but renders the wine muddy or turbid. It is in this deposit that the filaments of the fungus float. If white wines do not suffer from this disease of bitterness, they are exposed, particularly the white wines of Orleans and of the basin of the Loire, to the disease of greasiness. The wines lose their limpidity; they become flat and insipid and viscous, like oil when poured out. The disease declares itself in the casks or in the best-corked bottles. M. Pasteur has discovered that the greasiness of wines is likewise produced by a special ferment, which the microscope shows to be formed of filaments, like the ferments of the preceding diseases, but differing in structure from the other organisms, and in their physiological action on the wine. In short, according to Pasteur's observations, the deterioration of wines should not in any case be attributed to a natural working of the constituents of the wine, proceeding from a sort of interior spontaneous movement, which would only be affected by variations of temperature or atmospheric pressure. They are, on the contrary, exclusively dependent on the development of microscopic organisms, the germs of which exist in the wine from the moment of the original fermentation which gave it birth. What vast multitudes of germs of every kind must there not be introduced into every vintage tub! What modifications do we not meet with in the leaves and in the fruit of each individual spoilt vine! How numerous are the varieties of organic dust to be found on the stems of the bunches, on the surface of the grapes, on the implements of the grape gatherers! What varieties of moulds and mildews! A vast proportion of these germs are evidently sterilised by the wine, whose composition, being at the same time acid, alcoholic, and devoid of air, is so little favourable to life. But is it to be wondered at that some of these exterior germs, so numerous, and possessing in a more or less marked degree the anaerobic character, should find at certain moments, in the state of the wine, the right conditions for their existence and multiplication? * * * * *