209 



JOURNAL OF HORTICULTURE AND COTTAGE GARDENER. 



[ March 17, 1870. 



of nitrogen, still it ia constantly being decomposed, and sepa- 

 rates into its two elements. Ammonia is very soluble in water, 

 and is capable of being taken up into the sap, where the pre- 

 sence of ammonia can easily be traced, and this is, conse- 

 quently, supposed to be the chief sonrce of nitrogen as a food, 

 because it was given to the plant in a combined instead of an 

 nncombined form; but is there any proof that the nitrogen, 

 as it is separated again from the ammonia, is in any different 

 form to what it was before, and therefore more ready to enter 

 into combination ? I have mentioned the other two cases of 

 chloride end iodide of nitrogen, because by means of these 

 and other explosive compounds it is easy to obtain nitrogen 

 immediately it i3 liberated from other combinations ; but 

 chemists have never yet been able to trace any difference in 

 the nitrogen so liberated, and in no case is explosion by nitro- 

 gen formed by double decomposition — that is, by leaving its 

 combination with one element to combine with another, but it 

 is always liberated in the form of pure nitrogen, in the same 

 state in which it was before it entered into combination. 

 Oxygon is well known to have two forms, one of which is 

 called ozone, or nascent oxygen — that is to say, when oxygen 

 i3 liberated from one element it i3 more ready to enter into 

 combination with another. No such property as this has ever 

 been discovered in nitrogen, why, then, should the nitrogen, as 

 it is liberated from the ammonia, be different from what it ia 

 in the nir? or why should the plant be more able to assimilate 

 the nitrogen as a food as it is separated from the hydrogen in 

 the ammonia ? Every time the plant breathes through ita 

 lungs in the leaves it takes in nitrogen as well as oxygen, and 

 that, too, in conjunction with the hydrogen of the aqueous 

 vapour, and in every drop of sap that the plant takes up 

 in its pores and tissues nitrogen is also present. I do not 

 deny that ammonia is one of the forms in which what little 

 nitrogen is necessary to plants is assimilated as a food ; but 

 I cannot see what proof there is that it is the only substance 

 which does supply the nitrogen, nor is it, as I will afterwards 

 endeavour to prove, by any means the moat valuable ingredient 

 in ammonia, or, in other words, the value of ammonia aa a 

 manure is not due to the nitrogen it contains. This I will en- 

 deavour to show in another paper, in which I wish to point 

 out what, in my opinion, is the real value of ammonia as a 

 manure. 



The other ingredient, from which it is generally allowed by 

 agricultural chemists, that plants obtain their nitrogen, is 

 nitric acid. Nitric acid, NO3, 13 present in slight quantities 

 in the air formed by the combination of one part of nitrogen 

 to five parts of oxygen by means of electricity ; it is also found 

 in saltpetre (nitrate of potash), and is given to plants as a 

 manure as nitrate of soda. Nitrate of soda is supposed to in- 

 crease the bulk of the grain by giving nitrogen to the gluten in 

 the grain of the Wheat ; but it is worthy of notice, that its best 

 effect as a top-dressing is to stiffen the Btraw, and though 

 nitrogen is added in this way when nitrate of soda is used as 

 a manure, yet the straw of Wheat only contains ?>\ percent., 

 or only one part in three hundred of nitrogen ; but if we refer 

 to the analysis of the straw of Wheat, it will be found there is 

 7.0 per cent, of asb. Now, this ash is the mineral or inorganic 

 constituents of the straw, which are left after the straw is 

 burnt, and out of this TO per cent, is silica. Now, silica is one of 

 the most insoluble ingredients that a plant has to take up, and 

 nitrate of soda acta in one way as a manure by dissolving the 

 silicon, and enabling the plant to assimilate it, and it is well 

 worthy of notice, that though the Wheat plant is in this case 

 manured with a substance containing nitrogen, yet the straw 

 contains fifteen to twenty times as much silicon aa nitrogen. 



I will, however, leave the further discussion of the value of 

 the nitrates as manures till another time, as I am afraid I may 

 have sufficiently wearied your readers already, and will with 

 your leave continue the discussion in another number of your 

 Journal. — C. P. Peach. 



The Victoria uegia. — Thia magnificent plant has thriven 

 to an unprecedented degree during the past summer in the 

 Botanic Gardens at Ghent. Several leaves have attained a 

 diameter of 9 feet, and have supported a weight of 250 lbs., and 

 one even the enormou3 weight of 500 lbs. Seven of the 

 gigantic leaves completely covered the basin of 164 feet square, 

 and they were obliged to be removed to make room for the 

 young leaves which continued to develope in the centre. Every 

 four or five days a fresh flower appeared, which lasted only two 

 days, or rather two nights, opening in the morning of a perfectly 



white colour, diffusing about 5 or 6 p.m. a very powerful 

 odour of vanilla, closing the next morning at 8 or 9 a.m., open- 

 ing the same day towards evening, thia time of a beautiful car- 

 mine, and finally closing the next morning. The magnificent 

 leaves last through the summer ; the plant begins to dwindle in 

 October, and dies towards December. About this time the seeds, 

 which have been obtained by artificial fecundation, arrive at 

 maturity. They are sown in January, and appear above tha 

 ground in about six weeka. Their infancy is very critical ; but 

 once past thia period, the young plants grow with astonishing 

 rapidity ; the plant in the Ghent Botanic Gardens, unquestionably 

 the finest that haa ever been cultivated, arrived at ita full 

 development in five months. — (Nature.) 



SKELETONISING LEAVES AND FLOWERS. 



The seed vessels of the Winter Cherry, Henbane, and 

 Poppy, require a fortnight or three weeks if the weather be 

 hot. Leaves of Ficus elastica (Indiarubber Plant), and Mag- 

 nolia grandiflora, require Beveral months ; leavea of the Tulip 

 Tree, Poplar, and Maple, a fortnight ; leavea of the Holly and 

 Ivy two or three weeks. Ferns require a long time, and ao do 

 the Ieave8 of Beggars' Broom, Batchers' Broom, the Orange, 

 Lemon, and Camellia. 



Great care must be taken in choosing the leaves, as the 

 smallest speck spoils one. Many more should be placed in 

 the water than are needed, aa not more than one in twenty 

 will be perfect. The time required depends on the weather. 

 Beginnera examine them too Boon. 



The leaves should be put into soft water in a sunny situation, 

 taking care that they are covered with water. Evergreen 

 leaves may be skeletonised at any time, but deciduous leaves 

 not before the end of June or beginning of July. Seed vessels 

 must be operated upon when nearly ripe. When quite ready 

 for skeletonising 'put the leavea into boiling water to remove 

 the offensive smell. Remove the scum from the water. Brash 

 off the pulp with a rather hard brush. If the leaves are tender 

 bump them gently, which removes the pulp without disturb- 

 ing the nerves of the leaves. Pour clean water over them 

 until quite clean ; put them on blotting-paper to dry — a piece 

 of glass ia useful to brush them on. Tender leaves should be 

 floated ia water and caught oh a card, aa are fine Seaweeds. 

 Bleach with chloride of lime, and then wash them thoroughly 

 with clean water, otherwise they become yellow. It is better 

 not to bleach them until required for setting up. 



Thietles and Teazles look well when bleached, and aid much 

 in arranging a group. 



NOTES AND GLEANINGS. 



We have good grounds for believing that the Cuiswick 

 Garden will yet be preserved to the Royal Horticultural 

 Society ; at least, such a portion of it as will be sufficient for 

 all the purposes of a complete experimental garden, and by 

 which the Society will be enabled to preserve its neefulnefa 

 unimpaired. We need hardly say that such an arrangement 

 will be productive of great pleasure in the minds of all horti- 

 culturists. 



It ia proposed to erect a memorial over the grave of 



Mr. Samuel Bboous, late of the Inner Temple Gardens. Sub- 

 scriptions rnay be sent to the Treasurer, Mr. C. Wells, Bouverie 

 Street, Fleet Street, London, E.C. 



WORK FOR THE WEEK. 



KITCHEN GARDEN. 



Pretare fresh plantations of Globe Artichokes, if necessary, 

 by deep trenching and high manuring, for if encouraged in this 

 way they will, by udicioua thinning, continue much longer in 

 bearing. After planting out the winter Caulijioieers there 

 generally remain a number of small plants ; these, if pricked 

 out in a cool and shady border in rich soil, will make a succes- 

 sion, and form the connecting link between the principal 

 winter plants and the spriag-sown ones. Keep up a succession 

 of Lettuces, and let those raised in boxes in heat be pricked 

 out in a warm situation highly manured. Silver-skinned 

 Onions should now be sown for pickling ; the poorest soil in 

 the garden is the fittest ; work it when dry, and throw it into 

 high beds, the higher the better, and after sowing thickly treid 

 it as hard as possible. 



fruit garden. 



Finish all nailing of wall trees, and protect as much as pos- 



