ART. IV. Rejoinder to the Answer of the Author of the "Domestic Gardener's Manual," on Questions proposed to that Gentleman in Vol. VIII. p. 652. By Mr. J. MAIN. Sir, I FEEL very much obliged by your condescension in answering [p. 186.] so fully and so candidly the queries I took the liberty of proposing to you in a former Number of this Magazine. Having given your answer an attentive perusal, I must beg leave to say, that, from the whole of your arguments, it is to me sufficiently obvious that you have not perceived exactly the drift of my questions; your reply relates only to the augmentation of the elements of plants, while my questions referred to the formation of the organisation. This being the case, it is necessary to restate my questions somewhat more fully, and to add some brief comment, which, while it will place the former in a proper light, will also show to what they tended. My first question is simply this, Can the organic structure of plants be formed by or out of their juices? I call all juices of a plant the sap, whether in its crudest state, as pure water, or after its assimilation into the consistence of resin, gum, oil, milk, pulp, or jelly. In one or other of these conditions it is found in all plants, and either concreted or fluid, occupying the cellular, vascular, or tubular organs, or exuded therefrom, and appearing on the buds, in the flowers and fruit, or on other parts of the exterior. The sap is therefore an important constituent of the system, and quite distinct, in my opinion, from the organic frame which elaborates and contains it. I ask, then, is the latter formed by any possible aggregation of the former? in other words, are the pellicles of the cells, the sides of the vessels, or tubes of the structure, or the fibrous tissues of the various membranes, generated by associations of the rarer or grosser particles, or globules, of the sap? In your various respectable writings, and in your answer before me, you seem convinced affirmatively. This is your position; which (though supported by many great names) I deem untenable, and which, indeed, called forth the queries I presumed to propose to you. As proof of your opinion as to the organisable properties of the sap, you refer me to one of our first physiological authorities, and to an ingenious experiment made by that acute observer of nature. But as neither the high respectability of the experimentalist nor the result of the experiment itself can bear upon or alter the simple question proposed by me, I must decline giving any opinion thereon, more espe cially as the results of such experiments are not always uniform, differing according to the time and manner of performance; indeed, I might add, at the will of the performer. I have already alluded to the sap and membranous frame or structure of vegetables; but there is another equally important matter to be adverted to; I mean, the elements of vegetables. These, you say, are chiefly the constituents of water, viz. oxygen, hydrogen, and carbon; the chemical essences or bodies of which the vegetable frame is compounded; the pabulum by which it is enlarged, and without constant supplies of which a plant remains stunted, or would in the end inevitably perish. All this I firmly believe, and it is an admission which may appear at first sight to be corroborative of all you have advanced, and contend for, relative to the growth of plants; but I presume to think that a little further consideration and explanation will show, not only that` such distinction is just, and therefore necessary, in physiological investigations, but that they, viz. vegetable elements and vegetable organisation, should never be confounded together, so as to attribute to the former the power of generating the latter. Your ideas appear to be, that vegetable food, in conjunction with the vital energies and "chemico-electrical influences" of the earth and atmosphere, goes directly to form new organs. My opinion is, that nutrition received into the system goes only to increase the quantity of the elements already existing in the membranous fabric, serving to dilate and expand the same; not by addition of new cells, tubes, or fibres, but simply by enlargement of those already there. You assume that, by certain and peculiar combinations of vegetable elements acted on by "the great natural agents," new organic bodies may be generated. I humbly imagine this to be impossible; because such a phenomenon has never been seen, nor do we ever witness any vegetable body produced, unless it originates from a seed, propago, tuber, or other dissevered member of a plant. The organisation and specific structure are certainly rudimental; these are amplified, as already observed, by the elemental fluids absorbed by the receptive spongioles and pores of the cuticle, but not one additional cell can possibly be formed by any such augmentation of either gaseous or aqueous fluids. Can we suppose, with Buffon, that nature abounds in "living organic particles;" and that these, by concurring circumstances, associate by accident, and form vesicles, laminæ, tissues, fibres, and all other organic structure, in the same way as crystals are formed? Such doctrine, I presume, cannot be sound philosophy. If there were not determinate rudimental structure, the combinations of the introsuscepted aliment would be fortuitously arranged, and all specific structure would be irregular and confusedly disposed. These, my humble opinions of vegetable elements, accretion, and developement, will readily account for my second question, relative to the instances of organic bodies being formed out of inorganic matter, and on which I requested information. On this question you have been pleased to give as an instance the new growth of a potted vine, forced under your own eye. You solicit my attention to the new organisation exhibited in the elongated shoots, and ask whence it came. I feel perfectly confident in stating that the whole was contained in the buds before expansion, and the increase of the elements was derived from the manured earth and water with which the vine was supplied. The chemical elements of carbon, &c., contained in the expansible organisation of the buds were excited into action by heat and light; and, in every moment of the growth, fresh supplies of those elements were received to dilate the pellicle of every cell, elongate every tube, and engross every fibre composing the several membranes of the plant. I could prove by a thousand instances, were it necessary, that vegetable as well as animal organisation has rudimental preexistence. It is a fact admitting not a shadow of doubt; for, if it could be proved that the lowest and most insignificant of vegetables was self-produced, or if even the most inconsiderable portion of a vegetable organ could be formed from the mere union of vegetable elements, then, in the same way, we should not only have adventitious buds, flowers, and fruit, but adventitious herbs, and shrubs, and trees. Chemistry can form crystals, marble, and even the hardest of all mineral bodies, out of what was once in a state of fluidity; but can any possible combination of chemical bodies and powers originate the smallest Fúngus, or the minutest species of Infusòria? Some natural philosophers labour in vain to account for the primitive formations of plants and animals by their principles of science; and so, I dare think, will vegetable physiologists be puzzled, if they deny preexisting organisation. If, therefore, a plant cannot originate itself, nor acquire existence without a rudiment; so neither, it follows as a corollary, can the smallest member or appendage of a vegetable be developed, unless it arise from a preexisting congenerous membrane. (See Dom. Gard. Man., p. 274.) From these circumstances we arrive at, I think, a just and rational conclusion, viz., that vegetable sap is not organisable; because, in whatever state it is found, either in or out of a plant, it is always homogeneous; for instance, resin, gum, &c. That state of the alburnum called cambium, or pulp, is not sap, though fully charged with it. This I have endeavoured to prove elsewhere; but it would take up too much space to discuss it in these pages. I shall only add that I consider it impossible that either bark, wood, buds, leaves, flowers, or fruit can receive form, texture, or ligneous consistence adventitiously, even from the most elaborated and concentrated accumulations of that vegetable product the sap; and this doctrine I must continue to hold, until you or some other philosopher can clearly show that plants have, and may, come into existence equivocally. It is not necessary I should notice the other circumstances alluded to in your answer, relative to the secretions of animals, and transmutability of inorganic fluids and solids, because they do not bear on my questions, and, moreover, on these points we mostly agree. But, however you may receive or reject what I have advanced as explanatory of the real bearing of the questions proposed to you, be assured, Sir, that I feel much obliged by the civility which dictated, and the valuable illustrations of the elements of plants contained in, your answer. I regret much my ignorance of chemical science, and consequent incapacity for treating my view of the subject as it might be treated. All I know of that excellent science I have gleaned chiefly from yourself; and it is my sincere opinion that you have rendered essential service to practical gardening, by having united the two studies more intimately in the Domestic Gardener's Manual, than had been done by any previous author; and I flatter myself with the hope that, in all your future experiments and observations on vegetable phenomena, you will have an eye to the distinction, which I have so feebly tried to point out, between the enlargement of the vegetable frame, and the augmentation of the elements. It is in your power to do justice to the subject (should you approve the doctrine); and such a disquisition from your pen, appended to future editions of the Domestic Gardener's Manual, would be very serviceable to practical men. With best wishes that you may be long able and inclined to prosecute your studies, in the different branches of science you have chosen to illustrate, May 4. 1833. I remain, Sir, yours, &c. J. MAIN. * Vegetable Physiology practically applied to the Cultivation of the Garden, the Field, and the Forest; now in the press, in one small volume 8vo. Orr, Paternoster Row. Sir, To the Conductor of the Gardener's Magazine. I DARE not directly presume to address my gratuitous respondent, Joseph Hayward, Esq., author of the Science of Horticulture, &c. &c., and therefore trust to your kindness to give insertion to a very few words by way of rejoinder to the observations of that gentleman. (p. 192.) In the first place, I ought to consider it an honour that any question proposed by me should attract the notice of one who has distinguished himself so much by his writings on the science of both farming and gardening. Secondly, my thanks are due for his merciful consideration, in refraining to give an answer which I could "not understand; and, moreover, for the very homely instance which he has been pleased to give of the organisable properties of my "mother's milk,' which, he assumes, gave me, during babyhood, bones, legs, arms, and all other appurtenances to boot. These, however, I humbly imagine, I possessed long before I yet had blest my poor dear mother's sight. No doubt, that maternal fluid, gave me what Sir John Falstaff called thewes; but I much question (foolishly perhaps) whether, if I had sucked till now, I ever should have had another head or an extralimb. Mr. Hayward can hardly be serious in referring me to the earthy deposit on the inside of a tea-kettle; for surely the most consummate science would fail to prove that to be organised matter. But this reference, I am fully persuaded, was only a slip of the pen; and therefore, as in candour bound, I willingly exercise that tribute of compassion due to any man of science who inadvertently writes what, on reconsideration, he must feel he never could intend. I shall not add a blemish to the Gardener's Magazine by alluding to the style of Mr. Hayward's letter: that speaks for itself. I am, Sir, yours, &c. May 4. 1833. J. MAIN. ART. V. On the Effects of Terrestrial Radiation on the Processes of Vegetation; and some Account of the Chinese Method of propagating Fruit Trees. By J. MURRAY, Esq. Sir, Of all the sciences, it will be granted, on every hand, none is more connected with horticulture than that of chemistry. It is indeed its sun and centre; and, without the application of chemical laws and phenomena to horticulture, its principles |