177 
OF GARDENING AS A SCIENCE. 
NO. VIII. 
We brought our remarks upon humus to a close at page 155, and are naturally 
led to the consideration of the next great natural agent — water. We treat it 
numerically as second to earth ; but in point of importance it ought perhaps to 
hold the precedence. The view we propose to take of its composition and agency 
may induce others to arrive at that conclusion also. Few persons, in this reading- 
age, consider water as a simple element ; it is known by every philosopher to be 
a compound, consisting of the great elementary principles, hydrogen , two parts, 
and oxygen , one part, — both estimated by their volume or measure. But what are 
hydrogen and oxygen ? The simplest answer (and it is one which expresses 
ignorance) appears to be the following : — they are the constituent elements of 
water ; of that fluid which might be deemed the first of created things. 
The sublime experiments of Faraday have stamped peculiar grandeur upon this 
all-important fluid, for they have shown that it is the standard measure of 
electrical developments ; and therefore his Experimental Researches into Electricity 
ought to be perused by every natural philosopher with deep attention. If into a glass 
globe, containing one gallon of pure oxygen gas, a very fine jet tube be introduced, 
connected with a vessel (a gasometer is best) of pure hydrogen gas, and the stream 
issuing therefrom be ignited, before insertion into the globe, or by the electric 
spark when inserted, the combustion of the hydrogen will be effected by the 
agency of the oxygen, so that by the time the whole of the latter has disappeared, 
two gallons of the oxygen will have been consumed, and water, to the extent of 
the conjoint weight of the two gases, will be deposited in the globe. The late 
Dr. Henry, of Manchester, described the experiment very accurately in his Elements 
of Chemistry , and elucidated it with a woodcut, to which we refer our friends. 
It is our present object not to enter upon chemical minutiae, but simply to allude 
to phenomena which we have proved, and which may now be adduced in support 
of the electrical hypothesis of water. We view it, then, as the grand agent of all 
terrestrial meteorology ; as the depositary and medium of that elementary fire or 
essence which, through the primary agency of solar light, is the vital, stimulating 
principle of vegetable development and growth ; and coincidentally, as the instru- 
ment by which all manuring substances are brought into a condition to furnish the 
liquid aliment that is absorbed by the roots of a plant, and which we term sap. 
It is quite certain that in dry ground, wdiatever be its condition as respects 
manure or vegetable earth, no plant can continue to thrive. Hence, persons might 
be apt to suppose that water dissolves the manure, and conveys it in the state of 
liquid manure to the roots ; and such, or something very like it, was the received 
opinion of early cultivators. But good soil, that which is fit for the purposes of 
VOL. VIII.— -no. xcn. 
A A 
