62 



THE SCIENCE OF GARDENING. 



made to appear in due time. It has been 

 and will be our desire to avoid all dark and 

 mysterious terms — terms strictly profession- 

 al ; but as those who allude to scienc^, must, 

 to a certain extent, employ its phraseology, 

 words have been cited, which are in the 

 mouths of numbers, and arc to be heard 

 every day, though in point of fact, they are 

 very little understood, and much less appre- 

 ciated. 



In order to convey some idea cf the ex- 

 press meaning of these terms, a few words 

 may be said upon each of the vegetable 

 constituents above noticed, though not strict- 

 ly in the order in which they occur. 



Cnrbon. This substance enters largely in- 

 to the composition cf all vegetable products. 

 The word implies coal, or charcoal, and is 

 most readily interpreted by referring to the 

 charcoal of wood — that substance which re- 

 mains after its slow combustion, particular- 

 ly in those close iron retorts which are used 

 in the manufacture of pyroligneous acid. Its 

 quantity is very great, though various, and 

 may be stated as approaching to a little less 

 than half the entire weight of the dried 

 wood. 



0.r.yge>\ as far as we know any thing of 

 it, is an air or gas : — it is that vital princi- 

 ple of the atmosphere which sustains res- 

 piration, light and flame ; and exists inva- 

 riably, at every stason, in the proportion of 

 21 parts of every 100 of air, by measure. 



Nilrogtn is that inert portion of air re- 

 maining afcer the removal of the oxygen ; 

 it constitutes the bulk of the atmosphere, 

 and amounts in volume to 79 parts of every 

 100. It is not respirable, cannot support 

 flame, and is fatal to life ; its presence be- 

 ing easily shown by placing a lighted taper 

 under a bell-glass, the rim of which is im- 

 mersed in water to preclude the access of 

 air. As the taper burns, the water will 

 rise in the glass, and when the flame is ex- 



tinguished, (which it soon will be,) the fluid 

 will leave its mark at a point that will prove 

 one-siuth of the air to have been removed. 

 The experiment is not accurate, though very 

 near the truth. 



Hydiogen is the basis of water ; it exists 

 throughout nature wherever that fluid, or 

 moisture derived from it, exists. Separated 

 from water, it is revealed as a gas, the 

 lightest of all things that have appreciable 

 weight. It unites with oxygen in the pro- 

 portions by weight of 1 to 8, and by mea- 

 sure, of 2 hydrogen to 1 oxygen. If the 

 smallest electrical spark be passed into the 

 mixture thus proportionally blended, these 

 aerial elements explode violently wilh a 

 flash of light, and watery vapor is produced. 

 So, if a stream of galvanism be passed 

 through water, the two gases of that fluid 

 are again developed in the above menticn- 

 ed proportions. 



The phenomena attending this electriza- 

 tion of water are perfectly astounding, nor 

 can any adequate idea be formed of them, 

 without referring to the " New Researches 

 on Electricity," by Professor Faraday of 

 the Royal Institution. " One grain of wa- 

 ter," he says, " will require an electric cur- 

 rent to be continued for three minutes and 

 three-quarters of time to eflect its decom- 

 position, in quantity sufficient to retain a 

 platina wire yi-^- of an inch in thickness, of 

 any length, red hot, in contact with the air." 

 This quantity is equal to " 800,000 charges 

 of a Leyden battery, charged by thirty turns 

 of a very large and powerful plate electric 

 machine." " The chemical action of a grain 

 of water upon four grains of zinc, can evolve 

 electricity equal to that of a powerful thun- 

 der storm." These passages are sufficient to 

 convey " an almost overwhelming idea of 

 the extraordinary quantity or degree of elec- 

 tric power which naturally belongs to the 

 particles of matter. 



