"Searching investigations into the chemical activity of the different species of acetic acid bacteria would be not only opportune in the interests of science, but also highly important to the practice of the vinegar industry. In this business the employment of selected pure culture ferments is not yet regarded as a fundamental rule, everything being still left to the mercy of chance. ...there are two different methods of making vinegar. In one of them wine forms the raw material, this method being known as the Orleans process... There (as elsewhere) the work is still performed in the same manner as it was centuries ago as follows:—A number of oaken casks, each of a capacity of some 55 gallons, are arranged in rows in a chamber maintained at a constant temperature of 18° to 22° C [64° to 71° F]. In the upper part of the front end (head) of each cask a circular aperture (a few cm in width) is provided, through which the cask can be filled or emptied, and which is generally kept closed, whilst near it is a very small hole (vent) always left open for the admission of air. In normal work each cask is about half full. Before setting a new cask in work, it is scalded out several times with steam or hot water, in order to extract the sap from the wood, and is then "soured" by impregnating it with good, boiling-hot vinegar. About 1 hl. (22 gallons) of good, clear vinegar and 2 l. (0.44 gallons) of wine are then placed in the cask, another 3 l. of wine being added at the end of eight days, 4 to 5 l. more after the lapse of another week, and so on until the cask contains 180-200 l. (40 to 44 gallons). Then, for the first time, vinegar is drawn from the cask, and in such quantity that about 22 gallons are left behind in the vessel. From that time the cask "mother" is in continuous use, 10 litres (2.2 gallons) of vinegar being withdrawn every week and replaced by an equal quantity of wine. The "mother" casks may remain in work during six or eight years without interruption, but at the end of this period they will contain such a considerable accumulation of deposited yeast, tarter and , as to necessitate their being emptied and cleansed. A skin, known as vinegar flowers or mother of vinegar, and composed of acetic acid bacteria, develops on the surface of the liquid, and the manner and luxuriance of its growth enables the operator to judge the progress of the fermentation. However, at the outset the growth proceeds very slowly, since the wine employed mostly contains but very few of these bacteria. Consequently an opportunity is afforded for the development of rapid-growing injurious organisms, chiefly certain budding fungi, which consume the acetic acid. The aerobic "vinegar eels" also make their appearance."