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contain little or no sugary matter, the three stages of fermenta-tion cannot so distinctly succeed each other in them; but theconclusion is similar. The process operates differently, accord-ing as the proportion of the agent, water, is greater or less.When a quantity of vegetables, gathered into a heap, possessno more water than just enough to excite fermentation, heat isquickly evolved, and increases to such a pitch, that fermentingvegetables have been known to take fire ; the hydrogen of theplants is liberated ; and, combining with oxygen, forms water,copiously escaping in vapour, and forming in dew drops on de-tached objects; much of the carbon, combining with oxygen, iscontinually escaping in carbonic acid gas, which is felt in theair at some distance ; the bulk of the mass rapidly diminishes;its parts, which become very flaccid, mattirig together like felt,and excluding the air. It is worthy of remark, that heat in-creases as the parts coalesce more closely, and is greatest nearthe centre. Can this be from oxygen absorbed, or from the dis-engaged caloric of the vegetables ? The heat does not greatlysubside till the bulk of the mass be very much reduced. The ve-getables are then become brown, with a white mould forming onthem, and so brittle, that they may be rubbed almost to powderin the hand. As soon as rain falls, the structure of the veget-ables in a short time disappears. Without attempting to tracethe later changes which this residue undergoes, it shall only beobserved, that at length nothing is left but a little vegetable mould,consisting of insoluble or very refractory oxid of carbon, someearth, and salts.
Straw, immersed in water, and kept under it, in the averagetemperature of 50°, soon began to send air-bubbles to the sur-face. In a few days the water began to have a slight aciduloustaste, and somewhat of the smell of white wine. Soon after, theintestine motion increased, and the smell was like that of steep-ing flax, which daily became stronger, and the heat of the sub-ject rose some degrees above that of the surrounding tempera-ture. The heat subsided at the end of 27 days ; and the smellwas then that of litter which had been soaked some time inhorses’ urine. At the end of seven weeks the liquid was of adeep brown colour, and felt viscid. By evaporation, it left ahard, black, coally matter, which burnt with difficulty. It sof-tened when exposed to the air, and dissolved easily in water;and this solution gave clear evidence of its nourishing quality,when applied to the roots of young plants. The straw was alsoof a brown colour ; the fibres still retained some strength ; butthe parenchyma, by which they are united, was dissolved. Whencovered in the damp soil, it soon became black ; and against theend of the season, the organization was annihilated.
Such are the operations of that general law by which dead ve-.getables are prepared for nourishing those which are living, h