Observations on the vinegar plant / by W. Fraser.

  • Fraser, W
Date:
[1853]
Catalogue details

Licence: Public Domain Mark

Credit: Observations on the vinegar plant / by W. Fraser. Source: Wellcome Collection.

    18/26 (page 18)
    like minute dark lines, none of them exceeding the length of a cell, and representing, probably, portions of the cell- walls, which had been over-distended, ruptured, and disin¬ tegrated, by the heat of boiling. The liberation of the con¬ tents of the cells, by the destruction of the latter during the act of boiling, accounts for a very decided increase of acidity which is communicated to the vinegar by this process. A solution of treacle and sugar was made in a strong infu¬ sion of tea—a substance which contains nitrogen, and which from the readiness with which it gives rise to mould accom¬ panied by an acetous change in the liquid, is sometimes used domestically for the production of an inferior kind of vine¬ gar. A basinful of this mixture set in a dark place, and having several sheets of paper laid over it, was found, at the end of three weeks, to be covered with a thick coating of green mould growing upon a tough yellowish understratum, (Penicillium glaucum ?) It had lost nearly all its sweetness, without acquiring almost any acidity. It had a bitter, nau¬ seous, and mouldy taste. Viewed by the microscope, the understratum of mould appeared to consist of a thick web of capillary filaments, intermeshed in all directions, like the tangled roots of a bed of turf. At one extremity of these rootlets, the saccharine pabulum seemed to be imbibed—at the other, there were given off, in groups or flowerets, a num¬ ber of small and perfectly round spores, measuring about a third part of the long diameter of those of the vinegar-plant. These were uniform in size, generally arranged themselves when in the liquid, in straight lines, and did not appear to enlarge, or to undergo any sub-division or change, like the cells of the vinegar-plant. The grey and green dust consti¬ tuting the upper surface of .the mould, seemed entirely to consist of these spores. Another portion of the same solution had a vinegar-plant laid on its surface, and was covered, and placed in the dark as usual. At the end of the ordinary period, the plant was found in a soft, pulpy, decomposing state, distended with bubbles of gas, and covered with patches of mould. If any new plant had been formed, it was undistinguishable, hav¬ ing become involved in the general decay. These pulpy remains of the plant contained an abundance of vinegar-cells mixed together in all stages of their developement. Scarcely any of them, however, were found throughout the liquid,