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92 little yeast than from too much. It is impossible to describe by writing, the different anomalous appearances which take place in fermentation, and therefore equally impossible to say what should be done under certain circumstances, unless by personal inspection and examination; when the causes of the different anomalies which take place must be traced, and where unfavourable, rectified, before any permanent improvement can be expected.

M. Turpin has lately published his observations upon certain phenomena, which he considers sufficient to show, that the act of fermentation concerning which chemists have been so much embarrassed, is owing to the rapid development of infusorial plants. He states that all yeast, of whatever description, derives its origin from the separation from organic tissue, whether animal or vegetable, of special particles of extreme minuteness, which particles, after a certain time, rise to the surface of the fluids in which they are immersed, and there germinate. Their germination is caused by a certain amount of heat, and by contact with atmospheric air. The carbonic acid obtained by fermentation is ascribed to the infusorial plants. M. Turpin considers the act of adding yeast to liquids, when fermentation is languid, equivalent to sowing millions of seeds in a favourable soil. He calls the