352 



NEW ENGLAND FARMER. 



AVG. 



straws from the gleanings of the field of practical 

 science. 



Such as the wonderful journeys of a far fide of 

 carbon. We are too apt to overlook the wonders 

 of thint^s with whicli we are every day familiar, 

 and which are close to us, hut after a little mure 

 minute attention and examination, we begin to 

 find out a great many extraordinary powers in ob- 

 jects with which we seemed already familiarly ac- 

 quainted. 



Not the least of these, is the air ive breathe. It is 

 certainly one of the most extraordinary substan- 

 ces we are acquainted with, especially that portion 

 of it, the oxvgen, that n.ctive agent on which de- 

 pends our very existence, and by which so many 

 substances, by its chi-mieal combination, are pro- 

 duced. I will Confine myself to one of the pro- 

 ducts of the universal agent, the oxygen, by its chem- 

 ical combination with carbon, one of the simple el- 

 ements. 



Let us look round upon the bright green robe 

 in which the fields and trees are dressed ; look 

 round with wonder, for each leaf you see is apart 

 of the Almighty chemist's laboratory, and here, 

 amidst all this beauty, there is going on from early 

 morn to dewy eve, a work of such importance that 

 if it, were discontinued, the wh le animal creation 

 would soon cease to exist. Here, in these little 

 laboratories, is applied a mighty force, to which 

 the most powerful galvanic battery cannot l»e com- 

 pared, and here is a change effected, which estab- 

 lishments of human power, l)acked by human in- 

 genuity, has hitherto been unable to accomplish, 

 a change so utterly beyond man's power is effect- 

 ed. Let us look round with joy that so much 

 beauty shrouds the work-shop of the mighty chem- 

 ist ; look round with thankfulness, that so great 

 provision is made for o\ii- security and comfort, 

 and while we walk amongst these green leaves, 

 look with reverence, for the hand that works there- 

 in, is the Creator's. 



Let us now examine this mi^ihty laboratory, this 

 little leaf. Plants are not so much nourished by 

 their roots as many persons suppose ; the leaves 

 and the soft green covering of the stem perform a 

 much more important part in supplying the plant 

 with food. Plants grow by the absorption of wa 

 ter and the fixation of carbon ; of these substan 

 ces plants are almost entirely composed, and un 

 less they are supplied, the plant will die. The" 

 leaves are the principal agents in the absorption 

 and decomposition of carbonic acid, and the re- 

 tention of carbon, as a very simple experiment will 

 prove. Take a sprig of any succulent plant and 

 keep it in a dark place till you use it. Fill a tum- 

 bler three [larts full with water, and with a cle^in 

 tobacco pipe breathe into it for some minutes ; 

 then fill up the glass carefully, without wetting 

 the edges ; then drop in the sprig. (The glass 

 should be full, so as to make the water stmd 

 above the edges.) A flat piece of paper having 

 been laid on the top and a flat plate above, then 

 turned upside down, and put in the sunshine — 

 you will see globules form upon the leaves of the 

 sprig and rise to the upper end uf t!ie inside ol 

 the glass ; tliis is pure oxygen gas. Tlie carbon- 

 ic acid which the water absoi-I)ed has undergone 

 decomposition and the oxygen set free. 



The nutritious fluids of the plant, like the blood 

 of aaliu.ils, need exposure to the air before they 

 are fit to take a place in the organism cf the' 



plant, or form its tissue, and thus contact with the 

 air is brought about in the leaf, the anatomy of 

 wliicli, in some instances, may be seen without a 

 magnifying glass. If you split a stem down care- 

 fully at the point where aleaf is attached, you may 

 be able to detect the stalk of the leaf in connec- 

 tion with the central pith or medulla. A leaf is 

 composed of four layers of tissue, or two layers 

 folded upon themselves. The skin or cutiele of 

 the leaf is composed of compressed or condensed 

 cellular tissue ; beneath it, run the vessels which 

 bring the sap up from the root, wliich coming 

 from the medulla or pith, flows first over the upper 

 surface of the leaf, and then having been turned 

 under towards the stem, deposit new wood within 

 the bark. All the juices of plants are the same 

 till they pass along these vessels in the leaf where 

 they undergo a change. After having been ex- 

 posed to light and air in the myriads of vessels 

 which run along the leaf, the juice passing down- 

 wards on tlio outside of the stem, deposits woody 

 fibre in its downward course. This is chiefly com- 

 posed of the carbon which has been taken from 

 the air in the state of carbonic acid by the leaves, 

 which have really much more to do with the 

 nourishment of plants than the roots. 



In illustration of this, a bough of a tree round 

 which a plant of woodbine has been tightly bound, 

 will be swelled above the woodbine, not below, 

 proving that the growth of the tree takes place 

 from above, downwards. It may also be proved 

 l)y a simple experiment with a cord l)Ound tightly 

 round the stem of some rapidly growing tree. It 

 will be fi)und in a short time, the fibres sent down 

 from the leaves will swell the stem above the lig- 

 ature, while the portion of the stem below, will 

 not have increased in size ; never, therefore, sliould 

 the leaves of plants bo taken off, with the idea that 

 they have got more than the roots can nourish, 

 for, on the contrary, the leaves are the support 

 of the plant, where there is a free admission of 

 air. The beautiful green color of leaves depends 

 upon the absorption and decomposition of carbon- 

 ic acid in their vessels, and what we are l^reathing 

 out of our lungs to-day, may probably be incorpor- 

 ated with the tissues of a beautiful plant to-mor- 

 row ; perhaps with some blade of grass ; on that 

 grass the cow will feed and again appropriate the 

 carbon by absorbing it into her circulation and 

 forming the butter of milk ; and of that butter, 

 whose chief component part was breathed out from 

 the lungs a week before, we may eat, digest, and 

 again breathe out into the atmosphere . The adap- 

 tation of such a variety of important changes, so 

 diffetent in their charactei'S and the ends to be ful- 

 filled in sueha manner as all to be brought about 

 Ijy one universal agent, and the supplying of this 

 agent to all bodies which require it, by giving it 

 the gaseous form and making it encircle the earth 

 on all aides, may be regarded as one of the most 

 striking instances which can be adduced, of that 

 liarmony of adjustment which pervades the works 

 of nature. Yours, i&c, M. A Pekry. 



Watcrtown, July 1, 1853. 



The Swallow. — "Will some of our friends in 

 different parts of New England, be kind enough 

 to note the time of departure of the swallows, 

 and let us know. 



