GARDENING AS A SCIENCE. 



303 



good, you cannot give too much." A tree 

 is not all bones, and therefore something 

 must be considered besides its anatomical 

 structure — important as that may be. The 

 good, old-fashioned, substantial nourish- 

 ment must not be withheld, and a suita- 



ble ration from the compost or manure 

 heap, as usual, will by no means prevent 

 our orchards being benefitted all the more 

 by the substances of which they have es- 

 pecial need, in certain portions of their 

 organization. 



REMARKS ON GARDENING AS A SCIENCE.— No. 7. 

 BY DR. WM. W. VALK, FLUSHING, L. I. 



Air. — Prof. Liebig has undoubtedly put 

 forth some astounding disclosures respecting 

 certain atmospherical phenomena, which, 

 were they not familiar to most reflecting 

 minds, would be regarded with surprise and 

 awe. On one point he thus expresses him- 

 self: — "Although the absolute quantity of 

 oxygen contained in the atmosphere, appears 

 very great when represented by numbers, 

 yet it is not inexhaustible. One man con- 

 sumes by respiration about forty-five Hessian 

 cubic feet (nearly twenty-five English,) of 

 oxygen in twenty-four hours ; and a small 

 town like Giessen, with about 7000 inha- 

 bitants, extracts yearly from the air, by the 

 wood employed as fuel, more than 1000 

 millions of cubic feet of this gas." Every 

 act of respiration, of combustion, and of 

 fermentation, develops carbonic acid, which 

 passes into, and blends with the atmos- 

 pheric volume ; but this gas will be further 

 noticed at some future time. 



We have said that the atmospheric gases 

 are only mixed — not chemically united ; and 

 as this proposition has been satisfactorily 

 demonstrated by Dr. Dalton and other 

 chemists, the conclusion is both reasonable 

 and correct, that the atmosphere is not a 

 chemical compound in the ordinary accep- 

 tation of that term. It now remains to in- 

 quire what agency it exerts upon vegetable 



life ? In order, however, to afford scope for 

 reflection, let us refer to the Gardeners* 

 Magazitie (English) for 1S34, vol. x. page 

 207. There, is an article by Mr. N. B. 

 Ward, " 0?i groioing Ferns and other "plants 

 in glass cases, in the midst of the smoke of 

 London." This gentleman thus writes: — 

 " I was accidentally led, about four or five 

 years ago, to make some experiments on 

 the growth of ferns, &c., in closely glazed 

 vessels, from the following circumstances : 

 I had buried the chrysalis of a sphinx in 

 some moist mould in a large bottle, covered 

 with a lid. The insect attained its perfect 

 form in about a month, when I observed one 

 or two minute specks of vegetation upon the 

 surface of the mould. Curious to observe 

 the development of plants in so confined a 

 situation, I placed the bottle outside one of 

 my windows with a northern aspect : the 

 plants proved to be one of Poa annua, and 

 one of Nephrodium {Asplemum, Swz.) Jilix 

 mas. In this situation they lived for more 

 than three years; during which time no 

 fresh water was given them, nor was the 

 lid removed. The fern produced four or 

 five new fronds every year ; and the Poa 

 flowered the second year, but did not ripen 

 its seeds. Both plants ultimately perished 

 from the admission of rain water, in conse- 

 quence of the rusting of the lid." Thus 



