98 



NEW ENGLAND KAUMEK, 



OCTOBER S, 1S3*. 



ABSTRACT OP DR. DAKWIIV'S DISSERTA- 

 TION ON THE DISEASES OF PLANTS. 



fTdken Iroiti his work eutiiled " I'hyiologia, or tlie Philosophy 

 of Ajrirullure and Garcleniiig."] 

 The diseases of plains he classes under three 

 general heads ; those which arise from internal 

 causes, those from external elements, and those 

 from the depredations and injuries caused by in- 

 sects and larger animals. 



Many of the diseases of plants he attrihutes to 

 their irritahility. From this cause he conti-nds, it 

 is, that plants will not hear sudden transitions from 

 lient to cold, or even from cold to heat. Heat he 

 supposes acts as a stimulus to the i)lant, and if too 

 suddenly checked the plant is either injured or 

 destroyed. Hence the gardeners in northern cli- 

 mates deem it necessary to shelter tender plants, 

 such ns the flowers of apricots, as well from the 

 meridian sun as from the coldness of the night. 



He classes the internal diseases of plants as fol- 

 lows: 1. Mildew — this disease arises from a 

 plant of the fungus kind which penetrates with 

 its roots the vessels of the vegetahle to which it 

 adheres. The remote cause he supposes to he 

 some previous injury the plant had received from 

 internal disease. 



The remedy recommended is to thin the crop 

 and to admit a freer circulation of air. When it 

 is owing, which frequently is, to the dampness of 

 the soil, the remedy must be to drain the land, 

 and use the drier kinds of manure, as ashes, &c. 

 He further recommends sowing such land earlier 

 in the season, as he observes mildew is more apt 

 to prevail in the latter part of the season. 



This last is a very just remark ; every one must 

 have observed how very generally, if not imiver- 

 sally the pea is subjected to mildew in the autumn, 

 a circumstance which seldom happens in the 

 gprin"-. 2dly. Rust, which he describes as a fer- 

 ruginous powder spriidtled under the Jeavcs. He 

 supposes this also to be a vegetable production of 

 the fungus kind, and as it is probably owing to the 

 same causes, lie recommends the same remedy of 

 increasing the light and circulation of air, by 

 thinning the plants among which it appears. 3. 

 Clavus, ergot, or Speer. This is said to be an af- 

 fection of the seeds when they become enlarged, 

 and grow out of their natural size, pushing out 

 horns of a blackish color. The rye is apt to be af- 

 fected by it in France. He supiioses it to lie occa- 

 sioned by wounds made by insects. Duhamel 

 ascribes it to this cause. By the use of such dis- 

 cas«d grain by the poor, diseases have been produc- 

 ed of an alarming nature. Quere— is not the mal- 

 ady with which our Indian corn is affected, refer- 

 ribli) to this class of complaints ? It is an enlarge- 

 ment of the seed vessel, and frequently of the 

 seed, though it not uufreqnently appears in other 

 pans of the plant. May not that also be occasion- 

 ed by insects ? 



Ur. Darwin suggests no remedy for this com- 

 plaint. 4th. Ustilago, or Smut, when instead of 

 seed, the fruit produces a black meal, as occurs of- 

 ten ill wheat, barley, &,c. 



The Doctor mentions the usual practice of 

 steeping the wheat in salt ; in lime water and va- 

 rious other preparations, which is supposed to be a 

 preventive to the disease. He, however, quotes the 

 opinion of other respectable persons, that this is 

 an ancient error, and that the only use of .steeping 

 is to separate the light wheat from the heavy. 

 The same author cited by the Doctor, suggests 

 that the smut only takes place when wet weather 

 occurs at the time of the wheat's being in flower. 



and asks whether it is not probably owing to the 

 farina's being destroyed by the rain, and the con- 

 sequent faihire of impregnation of the embryo seed. 

 Dr. Darwin evidently leans to this opinion. Upon 

 this idea he suggests the sowing of the wheat in 

 rows considerably distant, and after a few days 

 sowing interme<liate rows, so that if wi;t weather 

 should destroy the anthers of one set of rows, the 

 alternate ones might supply the farina to their 

 stigmas when the weather becomes favorable. 



Qiiere — Would the stigmas of those plants 

 which had done blowing, be in a comlition to re- 

 ceive any beueiit from the farina of thosK which 

 should blow some days after ? We confess that 

 we doubt it; still in places very subject to the 

 smut, it might he well to try this experiment. 



5. Canker, or gaugrena vegetabilis, is what the 

 Doctor calls an ulcer of the hark, and is very des- 

 tructive to apple and pear trees. 



Mr. Knight has remarked that this disease is 

 most apt to attack those fruits which have been 

 long known and cultivated, and supposes it to be 

 a disease of old age. It is sometimes occasionc'd 

 by blows and injuries from the hoe, spade or 

 ploiiL'h. When the hark is thus wounded, this 

 disease frequently ensues. 



When a destruction of the bark is thus produc- 

 ed by external violence, it may possibly be cured 

 by the application of a piece of living bark from a 

 less valuable tree, nicely fitted to the wound and 

 bound on. 



When the hark is idcerated by this cankerous 

 disease, the parts afl'ected should he nicely cut 

 out, leaving the edges of the wounil smooth, so as 

 to admit the air freely, and prevent the lodgment 

 of moisture, nint the depredations of insects. 

 Some thick white paint should then he laiil upon 

 the bard wood, or laburnum, which is thus expos- 

 ed which may prevent insects from touching it, 

 and also the rains and dews from rolling it. The 

 paint should be so spread as not to Knich the edges 

 of the bark, as it might injure their growth by 

 its poisonous quality. 



6lh. The honey dew, which appears in the form 

 of small sweet drops on the surface of the leaves, 

 is supposed by Dr. Darwin to be a diseased exu- 

 dation or perspiration of the plant, but by others is 

 asserted to be the excrement of one species of in- 

 sect of the aphts kind. Dr. Darwin doubts this 

 latter opinion, because this aphis is often found <m 

 other trees and at other si'asons, without exhibi- 

 ting this phenomenon of the honey dew. 



T\w. honey dew, is observed to prevail most in 

 hot dry weather, and sometimes produces the 

 death of the leaf, at other times it is followed by a 

 black powder like soot, which covers the surface 

 of every leaf. He suggests no remedy for this 

 complaint. 



7. Sap Flow. This occurs when the alburnum, 

 or sap-wood of trees is wounded in the vernal 

 months, as in the birch and maple, and also in 

 the vine, branches of which not unfrequently 

 bleed to death. Another sap flow is said to ex- 

 ist about midsummer when the young buds are 

 Ibrming. Wounds at this season are therefore in- 

 jurious. When the loss of sap juice threatens the 

 injury of the plant, various remedies have been 

 applied by gardeners. Dr. Darwin thinks that a 

 piece of sponge bound close upon the woun<l 

 would be the most certain application, or a wire 

 twisted round the end of the branch cut oflf, so 

 tightly as to stop the circulation of juices, and to 

 destroy that pan which is above the ligature. 



8th. Secretio gummosa, gniii secretion, a iiiorliiil 

 production of gum which issues from irres eiibfr 

 from internal disease or from w omuls. \S\un 

 this happens to cherry trees, a gniii e.sndes likw 

 jium arable, which in dry wealh«;r hardens and 

 thus prevents the further disiiiarge of this nutri- 

 tive material, otherwise the tree weeps away ils 

 life from deficient nnurishuieiit. This slieiild he 

 prevented from c<U)tiiiuing to How by bind nig on 

 the part, previously maile sniooih by a kiiile, a 

 metallic plate, such as the lead in which tea is 

 wrapped, so as to prevent rain or dew drops fr<ut» 

 dissolving the hardened gum. .\ bit of sponge or 

 solt leather, or India riiliber might be Ixmnd on 

 under the lead till the wiuumIis healeil. Might 

 not a strong solution of green vitriol in water or 

 some ink, if applied to these bleeiling ves.<ils, 

 stimulate them into contraction, and prevent the 

 I'urther eflusion of gum ? 



ITEMS OF ECONOMY. 



On Whlte-ivaslihg Fruit Trees. We have em- 

 ployed lime while-wash on the irniiks of apple tretfS 

 to very great advantage ; but we would caution 

 our friends against applying it to cherry trees, as 

 s<une cases have been repoiled to us, in which its 

 efl'ects are believed to have been highly pernicious. 

 We are inclined to think that the application of 

 ashes is also unfavorable to this kind of tree. — 

 Gen. Farmer. 



The. Hoven in Caltk — is caused by their eating 

 too abundantly of green snccident food, as clover, 

 turnips, &c., and under bad management often 

 proves fatal. A pint of weak ley has been found 

 lo give relief. The Norfolk practice, according to^ 

 Marshall, is to give a beast salt and water ; ami if 

 this fails, a horn of salt anil grease, warm. The 

 Annals of Agriculture directs, as a specific cure, 

 l.ev.:n hi the most desperate cases, the following 

 dose: three-quarters of a pint of olive oil, and one 

 pint of melted butter or hog's lard, to be adminis- 

 tered by means of a horn or bottle. As a preveii-. 

 live, cattle should not be turned into rank clover 

 while the dew is upon it, nor stiflered to conlinne 

 more than an hour or two in it at a time, when 

 uncropped. — Cultivator. 



Hats manufactured by stenm. Messrs. Kenton & 

 Hare, are engaged in manufacturing hats entirelyi 

 by steam. 1 



We have examined the model of their machine 

 at their store, and were much pleased with the 

 in"eiinity of its contrivance. Near the boiler is a' 

 cylindrical receiver, provided with dashers on tliB 

 inside, not unlike those of a churn. A pipe in the 

 centre conveys the steam from the boiler to the 

 calender, in which the nap is placed. The work- 

 man is released troiii having liis hands at all in the 

 hot water, as was the case on the old plan, and by 

 the increased heat, the finish of the article is ren- 

 dered much more complete and elegant. — U. S. 

 Gaz. 



Flannel Factor;/. A company of gentlemen in 

 Rochester, N. H. we understand, are about putting 

 up a building 100 feet by 40, two stories high, to 

 be occupied by a new company of practical inaiiii-] 

 facturers, as a flannel factory. Their mill site It 

 a "ood fall, with abundance of water, — the power 

 sufficient tor very extensive operations. If suc- 

 cessful, it will add one more to a class of towns 

 unknown among us 20 years ago, but now of high 

 consequence as to their influence on business and 

 morals. — Portsmouth Journal. 



