ON THE GROWTH OF VARIOUS KINDS OF MOULD IN SYRUP.
Professor Balfour, the Professor of Botany in the University of Edinburgh, has read a valuable paper on this subject, at the Botanical Society in that city, in which he states that mould of various kinds, when placed in syrup, has a tendency to spread out and form a flat, gelatinous, and leathery expansion. This he shows by experiments, as follows:—Mould that had grown upon an apple was put into syrup; and in the course of two months there was formed upon the syrup a cellular, flat, expanded mass, while the syrup was converted into vinegar.
Mould that had grown upon a pear was also put into syrup, and the same result was produced. He also experimented in the same manner with various moulds that were growing upon bread, tea, and some other vegetable substances; the effect {374} produced, in most cases, was to cause a fermentation, resulting in the production of vinegar. In another experiment, a quantity of raw sugar, treacle, and water, were put into a jar, without any mould being introduced. When examined, after a lapse of four or five months, a growth like that of the vinegar plant was visible, and vinegar was formed. This plant was removed, and put into fresh syrup, which was followed again by the production of vinegar. It appears that, when purified white sugar only is used to make syrup, the plant, when placed in it, does not produce vinegar so speedily; the length of time required for the changes varying from four to six months. Dr. Balfour thinks this may possibly be owing, to the presence of some ingredient in the raw sugar and treacle, which may tend to promote the production of vinegar.
In connection with this subject, I may refer to the Vinegar Plant, which is considered by some eminent botanists to be an unnatural and peculiar form of some fungus. This plant, which has a tough gelatinous consistence, when put into a mixture of treacle, sugar and water, gives rise to an acetous fermentation. The vinegar, which is the result of this acetous fermentation, is of a syrupy nature; and when evaporated to dryness, a large quantity of saccharine matter is left. Various conjectures have been hazarded as to the origin of this vinegar plant; some stating that it came from South America, or other distant regions; and others that it is a spontaneous production. Dr. Lindley is of opinion that it is a peculiar form of penicillum glaucum, or common blue-mould. The general opinion appears to be, that it is in an anomalous state of mould, or of some fungus: and the peculiar form and consistence it assumes on different occasions, seems to depend upon the nature of the material in, or upon which, it makes its appearance.
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