By Mr. Deane, Vice President of the Pharmaceutical Society. Effects analogous to those produced by M. Ville (see last year’s volume, p. 755), with ammoniated air on the leaves of growing plants, have been observed by me, as the results of applying solutions of ammoniacal salts to the roots. My attention was first effectively turned to the subject about eight or ten years since, when an extensive grower of Pelargoniums, Fuchsias, and Roses, applied to me for some remedy for the sickly condition of his stock; which, if left unchecked, would insure a very severe loss to him. On examining the plants they were found to be in a starving condition, the roots having filled the pots and exhausted the soil; consequently, the leaves had lost their healthy green colour, and become very pale, with a strong tinge of yellow; the lower leaves were quite yellow, spotted, and falling off. The natural remedy was obviously fresh potting, but as the plants were already in pots best adapted to answer the purposes of the grower, some other remedy had to be devised. I therefore made a very weak solution of sulphate and carbonate of ammonia, and therewith watered the roots of the plants once a day, in the evening; and to insure any observed results as to the effect of the ammonia, certain rows of the plants on the stage of the greenhouse were selected for the experiment. In a few days the effects of the ammonia were most marked and satisfactory. The leaves began to put on a very remarkable appearance, the course of the veins, or spiral vessels, becoming perfectly green, the colour commencing at the basal portion of the midrib, and thence spreading through all the reticulations, until the tissues were perfectly restored to their normal and healthy condition; and, in fact, the plants thus treated looked more vigorous than they had ever done before, being much darker colour and firmer in texture. The contrast between these plants and those which had received no ammonia left no doubt about the efficiency of the application. I forget the effects upon the flowering of the Pelargoniums, but there was certainly no deficiency of flowers on the Fuchsias and Roses; they were, moreover, finer and better coloured than usual. On a subsequent occasion a gentleman’s gardener applied to me in a similar dilemma; he had a house full of fancy Pelargoniums preparing for a flower-show, at which he expected to take the first prize. Just as the trusses of flower buds were emerging, and there was every prospect of a good bloom, the lower leaves of the plants began to turn yellow and spotted, and then to fall off, leaving the plants bare, where the foliage was considered an essential point of beauty. I examined the roots and found them nearly filling the pots, it was therefore evident there