286 Mr. Mam's Bejoinder. 



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 noL. 

 sap, though fully charged with it. This I have endea- 

 voured 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 con- 

 sistence 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 necessaiy 

 I should notice the other circumstances alluded to in your 

 answer, relative to the secretions of animals, and trans- 

 mutability 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 inca- 

 pacity 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 Gar- 

 dener'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 veiy 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, 



I remain. Sir, yours, &c. 

 May 4. 1833. 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. 



