62S 



THE GARDENERS' CHRONICLE. 



nutrition of plants being now thoroughly explained 



52 " hardly any one part of tire "^St* 



not still, to a great extent, enveloped in doubt and 



utSaintv. The assertion that the ya ue of phos- 



pTorrfa^ ha^niy be'en ^discovered by chemists 

 during the last 10 years, is also one we cannot ^for a 

 moment admit; indeed Liebig himself, in his 

 Chemistry of Agriculture," refers to Saussuhe, o 

 show that the importance of phosphoric acid to 

 plants had long been known; and quotes from his 



; Sork, published nearly 50 years ago, be remark 

 "we have no right to suppose that plants could 

 exist without phosphate of lime." Or to cite a more 



' recent authority, we may refer to Sprkngkl, who 



; there is not a single known plant 



says, in 1832, - ,, ■% . ^ ■ 



which contains no phosphorus ;" and again, speaking 

 of the application of bone as manure, he observes 

 " that the phosphate of lime of bones constitutes 

 their chief value as manure, is proved by the well 

 known fact that burnt bones, which contain no 

 organic matter, act very powerfully on vegetation. 

 He also points out the value of mineral phosphates 

 of lime, such as fossil bones, apatite, &c, and states 

 that all marls which contain phosphate of lime are 

 excellent manures. It would in fact be easy to 

 show, that so far from it being true, that 10 years 

 ago "nothing was known in agriculture of phos- 

 phorus, or phosphate of lime" or that " no one knew 

 what it was in the bones which really acted," it has 

 been long known and fully recognised that phosphate 

 of lime or phosphoric acid is essential to the healthy 

 growth of plants ; this, therefore, cannot be claimed 



as a new discovery. 



The benefits which it is stated agriculture has 

 derived from the progress of chemical science, during 

 the last 10 years, are so vague and of so general a 

 nature that it is hardly worth while to discuss them 

 point by point very minutely. As regards the food 

 of plants, very little more has been done than to 

 confirm the experiments of older observers ; and as 

 for the explanations respecting rotation and fallow- 

 ing, we are quite at a loss to discover which part is 

 new — it seems that pretty nearly all of this part of 

 the scientific system of agriculture was already 

 known and acknowledged ; all that portion which 

 is really new is also, at the same, theoretical and 

 unconfirmed : and we must confess that Mr. 



stove passes in them to the extreme ends, then rises 

 to the upper divisions, and finally flows back into 

 the house over a water tank. In addition to this, 

 there is a hot-air box on each side of the fire, 

 through which external air is circulated, as well as 

 through hollow fire bars, discharging the great body 

 of heat (which they usually absorb), into the house, 

 and rendering it available for bottom heat. 1 he 

 stove is to be set in brickwork, and as the outside of 

 it is as hot as any part, much additional heat will 

 be obtained by leaving a space of 2 inches between 

 the stove and brickwork, they bringing externa^ air 

 to act on the two sides, and pass into the house. 



We understand that several of these apparatus 

 have been erected with great success, near Lime- 

 rick without the hollow fire bars, hot air boxes, 

 or outside casing, which have been late addi- 



The size of those in use (for houses, 50 to 



tions. — — ... . , 



66 feet), is 5 feet long, 3 feet wide, and 18 inches 

 high ; for larger houses it is proposed to make 

 them' 6 feet Ion*?. Our hothouse heaters will do 



well to study Mr. M'Sherry's model. 



VINE MILDEW.— No. I. 



The following Observations on the Vine Mildew, by 

 J. H. Leveille, D.M.,* translated from the French, 

 with remarks by the Rev. M. J. Berkeley, M.A.,F.L.S., 

 were published in the last Number of the " Journal of 



the Horticultural Society :" 



The gardeners in the neighbourhood of Paris have, 

 unhappily, too much reason for remembering the 

 damage done to their Grapes last year by the Oidium 

 Tuckeri. Under these painful impressions they are at 

 this very time watching their trellises every instant, 

 and turning up the leaves in search of the baneful 

 mould. Some return from their observations satisfied 

 with the result, but others alarmed, because they have 

 discovered certain spots on the lower surface of the 

 leaves, which they believe to be clearly due to its 



presence. 



It is, I think, useful to destroy this false notion, which 

 is>o generally diffused, and which is causing so much 



What is at this moment taken for Oidium 



Grapes, is 



met 



At 



Pusey's remark is not in any way really 

 or disproved by the reply of Baron Liebig. 

 the same time, having the greatest possible respect 

 for the labours of chemists, we must say that 

 we still look forward to them for much real assist- 

 ance in all departments of the arts of cultivation, 

 and that even if no very important practical appli- 

 cation of chemical science have been made during 

 the last ten years, that is no reason to despair of the 

 most valuable results hereafter. Such experiments 

 as those of Mr. Way on the absorptive power of 

 soils cannot fail in time to lead to improvements in 

 practice, though they may take years to carry out 

 and apply. Mr. Pusey observes very truly, that 

 larger experiments, not conducted merely in the 

 laboratory of a chemist, but carried out in a large 

 scale in the farm itself, and devised and executed 

 by a scientific man, are by far the most valuable 

 contributions which can be made to our knowledge 



anxiety. 



Tuckeri, the mould which destroys the 



merely the Erineum of the Vine, which has always 



existed, and which has never attracted much attention, 



because it is not, in point of fact, injurious. 



To avoid this mistake it will suffice to call to mind 

 that the Vine Erineum is constantly produced on the 

 lower surface of the leaves, where it forms spots vary- 

 ing in number and extent. It forms a lining to the 

 depressions, which are the counterpart of the blisters 

 which render the upper surface unequal and tuber- 

 culated. As soon as it begins to be developed the 

 surface purses up and exhibits a manifest change of 

 colour. It is at first white, rose-coloured, or pale violet ; 

 then it assumes a tawny or rusty tint ; even with the 

 naked eye it is clearly due to an anomalous develop- 

 ment of the hairs, which assume the appearance of 

 threads. To understand their nature perfectly it is 

 necessary to have recourse to the microscope, under 

 which they appear to be elongated, hollow, cylindrical 

 tubes, without any partitions through their whole 

 length, and absolutely empty. The membrane of which 

 they are composed is simple, uniform, without reticu- 

 lations, and of the same nature with the epidermis, of 

 which it is a continuation. This fact is beyond all 

 doubt, only the true cuticle forms no part of them, 

 because it has been destroyed or perforated by the 



t .. » e .. , _ w development of the subjacent cells. This at least seems 



ot the phenomena of vegetation ; and he quotes the to be indicated by a little circular line, or a slight irrc- 



excellent experiments of Mr. Lawes in illustration. 

 As may be supposed these experiments do not meet 

 with the approbation of Liebig, and in his reply to 

 Mr. Pusey, he characterises them as being u entirely 

 devoid of value as the foundation for general con- 

 elusions." In the last part of the Journal of the 

 Royal Agricultural Society, Mr. Lawes has published 

 the details of his experiments, and every one is, 

 therefore, able to judge for himself of their accuracy, 

 and the conclusions which he draws from them. 

 We shall reserve a few observations on those expe- 

 riments for another week. 



Among the matters of horticultural interest in the 

 Great Exhibition, there is a very humble one in a 

 corner of the hardware department, in Class 22 

 »o. 408, which, though late, and only just ' 

 marked, deserves to be placed on record. 



re- 

 We 



allude to a model of a heating apparatus, from Mr 

 Michael M'Sherry, of 3, James-street, Limerick) 

 intended for greenhouses, and similar buildings! 

 The model looks so much like a cubical iron box, 

 . that it may be well missed by any one who does 

 not take pains to find it. 



The plan of this apparatus is described by the 

 exhibitor in the following manner :— 



"To be made of boiler plate iron, with a metal 

 front, for heating by circulation of air. The flame 

 and smoke from the furnace pass under the stove to 

 the extreme end, and then rise at the two sides, 

 return to the front, and get over the top to the 

 chimney, where they do not escape until they pass 

 ail round the stove and heat every part of it The 

 air of the house to be heated is drawn in brick flues 

 under the floor to the under compartments of the 



gularity which exists at the base of each of the threads 

 of which the Erineum is composed. 



The causes of this anomalous growth of the hairs are 

 entirely unknown. It is regarded generally as the 

 result of the puncture of extremely small insects. This 

 explanation, however, notwithstanding the authority of 

 Professor Fee, has never appeared to me completely 

 satisfactory. Every one knows that when an insect de- 

 posits one or more eggs under the epidermis, or in the 

 substance of vegetable tissues, a great activity arises in 

 the vegetation, and an unnatural development of the 

 tissues; when, on the contrary, they are deposited on 

 the surface c f the leaves, their tissue is not affected, and 

 they experience no change. When an insect, then, has 

 introduced an egg under the epidermis, we ought to find 

 the egg itself, the cavity in which it is contained, and 

 the modification of the tissues which it has caused . 

 But neither eggs nor cavities arc ever observed, and 

 the epidermis alone is modified. It is very true that 

 we find amongst the threads of old patches of Erineum 

 larva* and their remains, as also mites and plant-lice. 

 But if we examine the upper surface of the leaf, we find 

 no aperture pierced by the insect, in order to escape 

 and live in a state of liberty ; the filaments do not pre- 

 sent the least solution of continuity in their whole length ; 

 their base always rests on the tissue of the leaves, their 

 free extremity is always obtuse and imperforate, and 

 their cavity does not inclose any traces of old skins or 

 excremential substances. Nothing then justifies the 

 notion that Erinea are like sails, bedemiara 

 cradles of insects. 



peated on those 

 and the Birch. 



Whether it re JmVf ^ 0l *> <W]^ 

 the accidental production diffe^l^^t 

 organisation and mode of develoL^? y m *** ^ 

 Though the Vine Brined x^^***£ 

 to the puncture of an insect with the 5S5?^ 

 its eggs, may we conclude that it is du? to £' 

 of the same insect made iu the leaves tt 

 of deriving nourishment from them i r * 

 Every one knows that, amongst inlets s» t . 

 terse which have the slenderest ^ "A, 



or tear the tissues in the act of suWon bV^S 

 different Darts of which +h^;^ ™~..xi . J m 



sible to conceive ; and as soon^Tu^proW.^? 1 



parts of which their mouth hZ^S*i 

 employ the most delicate acupuncture whi : 



<*** 



duced the juices ascend simply i n obedien^i* 

 of capillary attraction. May we suppose W * 

 at the same time they introduce some i^ifaS* 

 Nothing authorises this supposition ; and b2L* 

 it the case, what would be the condition of thTfii!* 

 our trees ? Not a leaf would preserve if!!? 1 

 all would be diseased. Much more most u£l 

 productions bear some proportion to the tinljt 

 insects ; but this is not the case ; and by? lL 

 eccentricity which is not rare in the humLn a£i i 

 refer to the most minute causes, the most i^ 

 effects' ; a locust may pass over without leJJ^ 

 traces, where those which a plant-louse - ^ 

 indelible. 



I repeat, then, that the Vine Erineum does not km 

 on the puncture of an insect, but is an elongriatfi! 

 epidermal cells, due to some unknown caaa. vfa 

 exists in the plant itself, as is also proved br tfefc 

 that the leaves while still rolled up and plaited edfe 

 traces of the affection. 



I have said enough to "enable any one to recofljn fc 

 Erineum, but to prevent its being confounded ii 

 Oidium Tuckeri, I think it right to call to Bad fc 

 description which I gave of that mould last var, hi* 

 the Society Philomathique (1850, August I). 



The plants on which the mould is developed fm 

 the same appearances as others, except that the km 

 of the year, the leaves, bunches, berries, and 

 in a word all the diseased parts, are covered with lip 

 thin white pulverulent down, which is visible it 

 distance, and which diffuses a very perceptible 

 smell. It forms on the leaves white cir 



•j.. 



;i«r''. 



spots, which resemble those of Erysiphe. This km. 

 when examined under the microscope, is fennels 

 slender branched articulated threads, which creep it? 

 the surface of the leaves. From different ponfcof a 

 primitive mycelium spring little erect 

 which are transparent, simple, and articaliied, a 

 which bear at their extremity three, four, or fin m 

 or elliptic simple hyaline spores, joined end toendfc 

 the beads of a necklace, and filled with extreme!? !■ 

 granules. These granules, when forced on. br ■ 

 pression between two plates of glass, are spfcna 

 transparent, and endowed with molecular motion. 

 These characters do not leave room for any 

 One of these productions is confined to w *m 

 surface of the Vine-leaves ; it is persistent, and doe** 

 disappear when rubbed; the other, ontheWJJ 

 attacks every part of the Vine except the old wp 

 and roots ; it is only temporary, and disappears ■ 



slightest friction. _,. , ,-- 



In questions of the diseases of the ^e, no** 



the Erineum seems to bear a cf^P^!^ 

 this was the case in 1835, when M. 5 ub ? c f "f^ 



sion. 



to the 



Natural H istory Society of Geneva to «£ 

 n Torula dissiliens, which occasioned « pj 



it 



tis 



MM. Alphonse De Candoll 



&c, the 



Jf, ni'Ieed, we meet by chance with 

 insects or larvse, the species are not so constantly the 

 •ame as to justify us in referring to them these acci. 

 dental forms of vegetation. These observations do not 

 rest merely on the Vine Erineum, but have been re- 



• He 

 D.M. 



rhtrches far la M.-Wadie d«« Vlgoen. jar J. II. I M\Ti 

 lixtrait de la Heme Horticole, No. riu 18 Juio, 1851. 



hire fail of thp leaves of the Vines ma gwgF 

 valley of the Leman Lake. M. Vallo , oi DgJ _ 

 that he recosnised in this plant the ^ w # 



.dolle and Dub) opp«J fc 

 view, because they were well acquaint 

 Erineum, and had made a particular A ^ 

 dissiliens. M. Vallot is, to a certain erf* ■ ^ 

 because he had seen neither the new" % ^ 

 figure which accompanies the memoi ^ 

 But the persistence of the Ermeum, sou ^ 

 which the Torula disappears, ought » ^s 

 doubts in his mind. It is sufficient to w ^ 

 the lower surface of the leaves to caus ^^ 

 So much is this the case that ^.^t** 

 remarks, in a note, » When I wished latej ^ 

 the Torula dissiliens preserved fj^&* 

 found that the act of drying had caaje ^ 



joints of this microscopic p ant to la •^p.e 

 only the diseased leaves of the Vine, , mu 

 of the parasite, and some very fi " e J?* erre^ 



The Oidium Tuckeri b more eas^ P J j, ., £ 

 not dispersed by a mere breath **£> -^W 

 theless, difficult to recognise its cliara ^rfj 

 mens, because the spores separate ■.* ■ ^i* 

 when it is dry, and nothing but m* 

 behind, which resembles tha of ^ Er J f t*f 



The certainty which has **""$&&. 

 taneous development of ™°™ d *™ iana , on d 

 and especially that of Botrytis ; BssaM . , #« 

 has made people believe though «r jj ,#J 

 diseases of vegetables and a nimal ,* & ^# 

 cause. Exaggeration has been pus £» 



It is well known now, from %*^«*£Z 

 caisne, that the nematoid invcehum, &W 



the epidermis of diseased Poto^ ^ ^ 

 Apples, &c, is consequent on f toy 



tions. It is the same with the v ^^ # w 

 Mr. Berkeley in England, and m. 











