396 



NEW ENGLAND FARMER, 



JUKE ao, 1833. 



For -Veic Yor/i Farmer. 

 VEGETABIjE PHYSIOIiOClY. 



LindkTfs Ledxirts. 

 1 HAVE liecn delighted, and witlial much instruct- 

 ed, in perusing tlie notice of a course of lectures 

 on hotauy, as connected with Horticulture, recent- 

 ly delivered hy professor Lindlet, before the Lon- 

 don Horticultural Society. I have seen nothing 

 better calculated to excite a taste for this delight- 

 ful science, or to render it subservient to the wants 

 of man. I hope soon to see the entire series ad- 

 vertised by our enterprising booksellers. There 

 aie some facts laid down by the professor, in the 

 analoiry wliich he draws between the blood of an- 

 imals and tlie sap of plants, that may be new, and 

 I presume not uninteresting, to a portion of your 

 readers, and which I take the liberty to send you 

 with some remarks, for publication. 



The necessity of alternating crops in husband- 

 ry has been imputed to a power in plants of elec- 

 ting from the soil a peculiar iood adapted to their 

 wants; and it is supposed, that as one crop ordi- 

 narilj' exhausted th« specific food of its species, a 

 succession could not follow without deterioration, 

 or a fresli supply to the soil of the needful pabu- 

 lum. But the Professor says, that plants absorb 

 aqueous particles indiscriminately ; "that the moist- 

 ure absorbed by the spongioles having ascended 

 to the leaves, and been elaborated there into sap, 

 returns, depositing by the way all the nutritious 

 particles it has acquired ; and at last throws oti'the 

 residuuui, in the shape of a spongy e.xcrescence, 

 at the root. These excretions, consisting only of 

 what the plant has rejected, are of course uufit for 

 the support of other plants of a similar nature, and 

 may be said (in relation to such) to poison the 

 soil." 



This goes to strengthen the argument in favor of 

 alternating crops, infield as well as garden culture. 

 It applies with particular force to the transplanting 

 of trees; and indicates the propriety of removing 

 all the soil from their roots, and even of wash- 

 ing them, instead of transplanting them with a 

 ball of earth, as is often the case, particularly with 

 evergreens. I have heard of the practice being 

 successfully adopted, observing the precaution to 

 prevent the drying of the fibres, so as to destroy 

 their functions. But as evergreens have always a 

 foliage to sustain, tho ball of earth becomes in a 

 measure necessary to preserve the spongioles 

 (mouth) it contains till new ones are formed, or 

 those injured by the removal resume their func- 

 tions. 



The experiments employed to illustrate the de- 

 posit of vegetable excrementitious matter, served 

 to show another remarkable analogy between ani- 

 mals and vegetables. " All poisons are either cor- 

 rosive or narcotic ; or, in other words, act cither 

 by over-stimulating or relaxing the system ; and 

 these different effects have been shown clearl}', by 

 various experiments, to be produced on plants. — 

 One branch of a common barberry was steeped in 

 a solution of corrosive sublimate, and another in 

 a decoction of opium, when, in a short time, the 

 vessels of the oHe were found to have become.turgid, 

 and of the other relaxed : the natural irritability of 

 the plant being, iu both cases, destroyed." To 

 this susceptibility in plants to the deleterious ef- 

 fects of poison, I have no doubt we shall be able 

 to trace the new maladies which injure our fruit 

 trees. I consider .that the disease which has de- 

 stroyed many of our plum trees has been proved 

 to originate with an insect, which punctures th 



branches, and injects a subtile corrosive poison 

 into the sap vessels. The precaution, when, it has 

 been adopted, of cutting off and burning the affec- 

 ted parts as soon as they are discovered, and of 

 thereby destroying the germ of the insect, has had 

 a happy effect in diminishing the evil. 



While employed in these remarks, I have met 

 with the observations of M. Macaire, inserted iti 

 the French Journal of Science and Arts, up- 

 on this branch of physiology, which coincide 

 with those above quoted from Professor Li.nd- 

 LEy. " A certain portion of the juices," says M. 

 Macaire, " which are absorbed by the roots of 

 plants, are, after the salutiferous portions have been 

 extracted by the vessels of the plant, again thrown 

 out by. exudation, from the roots, and deposited in 

 the soil. It is probably the existence of this exu- 

 ded matter, which may be regarded, in some meas- 

 ure, as the excrement of the preceding crop of 

 vegetables, that proves injurious to a succeed- 

 ing vegetation. It has been compared to an 

 attempt to feed veg-etables upon their own ex- 

 crements. The particles which had been deleteri- 

 ous to one tribe of plants cannot but prove 

 deleterious to plants of tho same kind, and prob- 

 ably to those of some other kinds, while they 

 may furnish nutriment to another order of vegeta- 

 bles. 



Admitting what these eminent physiologists 

 seem to have demonstrated, that plants throw 

 oft' by their roots whatever is deleterious to 

 their health, the conclusion drawn from the fact 

 does not seem rationally to follow — I mean, it 

 does not result that the cause of the deterioration 

 of the second is to be found in the deposits made 

 in the soil by the first crop. Wheat, in particular, 

 is found to deteriorate on ordinary soils, and on 

 few will it bear repeating ol'tencr than once in three 

 or four years ; yet there are soils which will bear 

 cropping with this grain for many successive years 

 without diminution of product. Such is par- 

 ticularly the case in the valleys of the tienesec 

 and of the St. Ijiwrence. Here, upon their theory 

 must be an annual accumulation of poison, ani 

 yet the plant does not seem to be injured by it. 

 This excrementitious or poisonous matter has, 

 combined with aliment, once passed through thi 

 sap vessels of that plant without injury; and Vfliy 

 not, combined with the aliment which is constantly 

 preparing in the soil, may it not prove equally 

 innoxious, the second year, to a like plant. I 

 suspect it is not so much the presence of a poison, 

 as the absence of food, which causes the falling 

 off" in the product. These gentlemen admit that, 

 although plants cannot elect, in the soil, the food 

 which is adapted to their wants, they can and do 

 retain none other in their system. This is admii- 

 tiiig that there is a specific food adapted to eaclj 

 species ; and that what is aliment to one kind may 

 prove a poison to another. Is it not rational then 

 to conclude, that as a plant appropriates to itself all 

 the salutiferous or alimentary particles which en- 

 ter its sap vessels, the subsequent infertility to this 

 kind of crop is owing to the soil being exhausted 

 of its particular or specific food ? The annual ap- 

 plication of manures, containing this specific food, 

 is generally successful in counteracting this sterili- 

 ty. The deep alluvial deposits of vegetable and 

 animal matter, which have lieen accumulating for 

 centuries, and to which I have alluded, seem to 

 afford an inexhaustible supply of the specific pa- 

 bulum of wheat, without any indication of the 

 imaginary poisons. B. 



From the New York Farmer. 

 CIRCULATION OP SAP. 



Professor Lindley gave a course of lectures- 

 the last summer, before the London Horticidtural 

 Society, illustrating the relation of Botany to 

 Horticulture. Although there is no one to whose 

 opinions I pay a higher deference, there is one 

 fact, nevertheless, which the Professor has advan- 

 ced, that I am not able to reconcile with my ideas 

 of vegetable physiology, viz: that the sup of plants 

 sinks in tvintcr. If the Professor means ^^hat the 

 language of the abstract seems to imply, that the 

 bole and branches of trees are destitute of sap dur- 

 ing the cold of winter be seems to have disproved 

 the position, by another fact, which immediately fol- 

 lows, to wit that the sap appears first in motion at 

 the extrcmitt) of the branch. — This truth has been 

 corroborated by many experiments. Branches of 

 the vino, of the peach, &c. have been introduced 

 in winter and spring into the warm temperature of 

 a green-bouse, and have developed their leaves 

 and blossoms, while the bole and roots remained 

 froziii and dormant in the external atmosphere 

 and earth. How can this happen if the sap, which 

 is tho nourishment of plants, had entirely forsaken 

 these branches, and sunk into the earth? There 

 are some animals which, like plants, remain torpid 

 and take no nourishment during the winter; and 

 yet it would be preposterous to suppose that they 

 were, during this time, destitute of blood. With- 

 out having examined the subject I suspect that 

 the blood of such animals is, like the sap of plants,, 

 desiitute of the common animal heat; and that both 

 the animal and vegetable become torpid for want 

 of extraneous warmth, (for both show and evince 

 vitality and life on the artificial application of this 

 agtMi,) and that the genial warmth of spring- 

 merely awakens their dormant powers into ac- 

 tion. 



When we consider the expansibility of water, 

 and that its volume may be hicreascd eighteen 

 hundred times by the agency of heat, we may 

 readily aecoimt fi)r the great diminution of the 

 volunio of Bup in plants in the autunuial and win- 

 ter months. This volume is further reduced by 

 evaporation of its aqueous particles, after it ceases 

 to rise in the autumn, and the leaves have lost tho 

 power of elaborating it. I believe the circulation 

 in plants is impeded, and sometimes wholly arrest- 

 ed, by cold or the absence of heat ; but cannot 

 believe that the sap sinks in winter more than tit 

 any other season. 



Let us look at the process of nature. " The sap 

 appears first in motion," says Professor Lindley, "at 

 the extremity of the branches." And why? because 

 theso extremities, being minute, are more sensi- 

 tive to temperature than the large limbs and bole; 

 and the vernal warmth, upon the known laws of 

 caloric, first increases the volume of their fluids; 

 so in the experiments of the green-house. The 

 branches introduced have their vessels distended 

 by the agency of heat, the sap is so propelled to 

 the buds, for it cannot circulate down through the 

 frozen wood, and the leaves and blossoms are 

 ex[)anded, ere the circulation has commenced at 

 the outside of the house, and when, of course, no 

 supply could come from the roots. From this 

 view of the subject, I cannot agree with the Pro- 

 fessor, that the sap of plants sinks into the roots in 

 autunm ; that it becomes concentrated, and perhaps 

 quiescent, by the effects of cold, is true ; and it is 

 no less true, that heat expands its volume, and 

 causes it to circijlate, in the spring. B. 



