Maivh ai, 1872. ] 



JOURNAL OF HORTICULTURE AND COTTAGE GARDENER. 



253 



host, bocauso it coutaius all the constituents of former crops, 

 and is therefore best suited for the production of future ones. 



When Mr. Peach states that nitrogen iu the form of am- 

 monia is useful, because iu that state it forms a powerful 

 solvent for every land of carbon, I fear he states what he can- 

 not prove by experiment. Did he ever try to dis^ulve the 

 diamond, the purest form of carbon, with ammonia, or did he 

 ever dissolve a particle of charcoal with it '> How, then, can 

 ammonia bo a powerful solvent for every kind of carbon ? It 

 is quite true that powdered charcoal has been found very 

 beneficial to plants, and that only when ram water contain- 

 ing ammonia has been used for watering ; for if distilled 

 water has been used, and no ammonia allowed to come iu 

 contact, the plants have soon sickened and died, but the 

 charcoal has not been dissolved by the ammonia, nor taken 

 up into the pjant. It has the property of absorbing into its 

 pores an enormous quantity of ammonia, as well as of carbonic 

 acid gas, which the excess of rain water has the power of 

 dissolving out again, and bringing it iu contact with the roots 

 of the plant, or of evaporating with it into the plant's atmo- 

 .sphere, so that the leaves can also absorb it. 



It is well known that Liebig, many years ago, insisted on the 

 doctrine that, providing all the mineral constituents required 

 by plants wero present in the soil, all the carbon, as well as 

 the nitrogen, in the form of ammonia and nitric acid, would 

 be fui'nished by the atmosphere. This was called the mineral 

 theory. Iu his later wi-itings he has modified this view, 

 simply because the plant canuot get sufficient in the time 

 assigned to its developmeut ; but he clearly proves that nitro- 

 genous manures, as such, can only be of use when all the 

 mineral constituents required by the plant are already in the 

 soil. He also estabUshed the fact, now universally received, 

 that carbon is conveyed to plants not in any organic combina- 

 tion whatever, but as a gas formed by the aid of the atmo- 

 speric oxygen, and called carbonic acid. 



Reverting to the humus theory, as insisted on by Mr. Peach 

 iu the .Journal some time ago as the source of carbou to plants, 

 the true value of humus iu the soil may thus be stated. As 

 living organisms feed on the carbon restored to the air by 

 their defunct predecessors, aud as humus is but the debris of 

 previous vegetation iu a soil, the carbonic acid developed by 

 its decay must play a proportionate jart in nourishing the crop 

 then in com-se of growth. Hence the necessity of an atmosphere 

 within the soil to oxidise the humus, and thereby to reduce 

 its carbon from the org.anio to the mineral condition, so as to 

 make it assimilable by plants. The necessity of such an under- 

 ground atmosphere is an established fact, air being as essential 

 as warmth aud moisture to the development of plants. 



In this way do decajing organic bodies replenish the atmo- 

 sphere, whether above ground or below it, with gaseous carbou, 

 which the atmosphere in its turn conveys to the plants, whose 

 leaves appear to inhale it as gas, but to whose roots it is sup- 

 plied in watery solution. The carbou of the plant and the 

 carbou of the soil have but one primal origin — the atmosphere. 

 From this source the carbon constantly flows ; to this reservoir 

 it as constantly retui'us. The humus of the soil and the tissues 

 of plants are but successive resting points for cai-bon in its 

 ch'culating course. 



The question of plants taking up free nitrogen from the 

 atmosphere was studied and experimented on by Boussingault 

 and others for more than twenty years, aud by a masterly and 

 luminous induction the nitrogen of the atmosphere was proved 

 to be inactive in vegetation. Lawes and Gilbert, in an ela- 

 borate paper pubUshed some time ago, record the results of a 

 series of valuable experiments on this point, and their con- 

 clusions are confirmatory of Boussingault's views — that all the 

 nitrogen elaborated in plant-tissues are derived entu'ely from 

 ammonia and nitric acid. 



With respect to the hydrogen in plants, Mr. Peach argues 

 that because water is such a stable compound when once 

 formed, requiring such very powerful agents for its decompo- 

 sition, therefore it is very unlikely that it should give up its 

 hydrogen to plants. Did Mr. Peach ever watch the plants 

 growing m an aquarium in bright sunshine ? If so, he might 

 have seen the leaves covered with minute bubbles of gas, and 

 after a time, when the water beopme saturated with this gas, 

 ho might have seen large bubbles of it ascending through the 

 water and escapmg into the atmosphere. If he had collected 

 some of this gas, he might have proved that it was pure oxygen 

 escaping from the leaves of the plant, while the plant was 

 vigorously mcreasing in size and form. Thus the humble 

 pliant has the power of decomposing water as well as carbonic 



acid, assimilating both hydrogen from the water and carbon 

 from the carbonic acid under the stimulating influence of solar 

 light. 



In reference to kon in plants, Liebig in his " Natural Laws 

 of Husbandry" says, " Wo kuow the part which iron perfoi-ma 

 iu the animal economy. It is present in the animal organisms 

 in no greater proportion than in the seed of the cereals, and 

 we are fully con^-inoed that without a certain amount of iron 

 in the food of animals the formation of the blood corpuscles, 

 the agents of one of the chief functions of the blood, is impos- 

 sible. Hence by the laws of dependence, which link together 

 the Ufe of animals and plants, we are compelled to ascribe to 

 the iron in the plant also an active part in its vital functions, 

 so material that the absence of that metal would endanger the 

 very existence of the plant." Iron, like all the other minerals 

 required by plants, is dissolved by carbonic acid in water, and 

 thus is absorbed by the roots of plants ; and as all clays and 

 strong soils contain abundance of iron, this may be one of tho 

 reasons that such soUs are so suitable for Roses. 



It appears, then, that no matter which has been organised 

 can serve as food for plants until it has undergone decomposi- 

 tion, and that it is solely in the constant and regular supply of 

 carbonic acid it affords that vegetable mould is more adapted 

 for the support of vegetable hfe than any other kind of soil. 

 And thus we see a very important difference in the character 

 of the members of the animal and vegetable kingdom ; for 

 the first are entirely dependant for their nourishment upon 

 matter that has been previously organised, and derive then' 

 support either from vegetable or animal bodies. The latter are 

 dependant for their growth only upon the materials supplied 

 by the inorganic world, although their increase may be advan- 

 tageously assisted and stimulated by those which they derive 

 from the decay of the former. Do we not here trace a beauti- 

 ful harmony between the various parts of the great scheme of 

 creation? for had vegetables, hke animals, been dependant 

 upon organic matter, both classes of beings must have gradu- 

 ally disappeared from the face of the earth, since the spon- 

 taneous death and decay of a large proportion of them is con- 

 stantly restoring to the inorganic world the elements they have 

 held for a time iu those pecuUar forms which are termed or, 

 ganic, and thus the amount of organic matter would be con, 

 tinually diminishing. But vegetables, holding an intermediate 

 station between the mineral and animal creation, bring them, 

 as it were, into conuection with each other, preparing, as they 

 do, from Uttle else than the air aud the water of the globe the 

 materials for the sustenance of the oouutless mUhons of 

 beings which move upon its surface, and which, when their 

 allotted period of existence has expired, restore by their decay 

 the elements required for the support of the vegetable life of 

 their suooossors. — J. M., Burtoii-on-'Trciit. 



ANTHURIUM SCHERZERIANUM. 



Too much praise cannot be accorded to this extremely beau- 

 tiful plant, and for exhibition and decorative purposes it ranks 

 as one of our best. The curious and brUhant-coloured flowers, 

 so different from any others of those belonging to our stoyo 

 plants, are deservedly admhed by every plant-lover. It is 

 much to be regretted that there are many spurious varieties of 

 this valuable plant ; but such beiug the case, it is necessary to 

 be very pai'ticular when purchasing a plant to be sure to get 

 the best variety — I mean the large-spathed and briUiant- 

 coloured variety, which I consider to be the best ; but unless 

 you can rely upon the honour of the person from whom it is 

 obtained, you had better see the plant in bloom beforehand. 



I think i may say, without fear of contradiction, that it is a 

 plant of very easy cultiu'e— at least I have always foimd it sc — 

 but I am not so certain whether I am justified in calhng it a 

 stove plant, as in several cases I have found it do very well 

 uuder cool treatment. I generally grow it in the stove, and 

 when in flower turn it into a cool house, where it lasts in 

 bloom for a very long period. It may be interesting to some 

 if I describe my mode of growing this beautiful plant. 



I have found two parts good fibry peat aud oue part turfy 

 yellow loam, with a free admixture of silver sand, .and a 

 handful of charcoal the size of a walnut, suit this plant very 

 well. Iu pottmg, I fill the pot two-thirds full with crocks, 

 putting the larger ones at the bottom and the small ones on 

 the top, covermg them with a layer of sphagnum moss, so as 

 to secure that perfect drainage so highly necessary. I then 

 nearly fill the pot with the soil prepared, turn out the plant to 

 be potted, and, removing the gi'eater part of the old soil from 



