were present; but phosphate of potassium is absorbed by the plant, and this coming in contact with the albumenoids renders them soluble; they can now pass through the cell-walls of the stem, and upward into the seed, where they are stored for future use. Phosphates are also necessary for the production of certain fats, of which they form a part, for the fat of the horse-chestnut and oak contains a small percentage of phosphorus. Of the other salts sucked up by the roots, the sulphate of lime is worthy of mention, as it is necessary to the formation of albumenoids, sulphur being an essential ingredient of these matters, whereas phosphorus is not; and also many essential oils require this element in their composition, and it is to its presence that the oils of black mustard and garlic owe their peculiar pungency. The function which many of the other ingredients found in the ashes of plants perform is still somewhat uncertain, but all experiments indicate that potash, lime, and magnesia (the alkaline earths, as these last two are termed) are indispensable to the life of the plant, and that the absence of iron is accompanied by abnormalities of growth. When a soil contains no iron, and this does not occur naturally, the foliage loses its green color, the loss being due to the non-formation of chlorophyl, or the green coloring matter, and where this is absent, the process of assimilation as performed by the leaves ceases, and therefore the plant is in an unhealthy condition; when we come to speak of the respiration and assimilation of plants, an explanation of these terms will be given, but at present a few words on the use of potash, soda, and silica will not be out of place; but we will not attempt to dilate on the uses of other ash ingredients, such as chlorine, for, as before stated, there is no accurate information concerning them, but that they are requisite is certain, while what their functions may be is uncertain.