OF GARDENING AS A SCIENCE. 
67 
4. Hydrogen is the basis of water ; it exists throiigliout nature wherever that 
fluid, or moisture derived from it, exists. Detached from water, it is revealed as a 
gas, the lightest of all things that have appreciable weight ; it therefore has been 
adoptedby chemists as the unit upon which the comparative atomic theory establishes 
its specific weights. Hydrogen unites with oxygen in the proportions by w^eight 
as 1 is to 8 ; and by these figures the weight of water is expressed : — and by 
measure in the proportions of 2 hydrogen to 1 oxygen. These aerial elements being 
thus blended in the above-mentioned proportions, explode violently with a flash of 
light if the smallest electrical spark be passed into the mixture, and watery vapour 
is produced. 
If a stream of voltaic electricity (galvanism) be passed through water, the two 
constituent gases of that fluid are again developed in the proportions above- 
mentioned. 
The phenomena attending this electrization of water are so astounding, that we 
feel obliged to refer to the " New Researches on Electricity," by Dr. Faraday, of the 
Royal Institution, in order to convey any adequate idea of them. " Otie grain of 
water will require an electric current to be continued for three minutes and three 
quarters of time to effect its decomposition, in quantity sufficient to retain a platina 
wire ^i-^ of an inch in thickness, of any length, red hot, in contact with the air." 
This quantity is presumed to be equal to " 800,000 charges of a Leyden battery, 
charged by thirty turns of a very large and powerful plate electric macliine." The 
chemical action of a grain of water upon four grains of zinc can evolve electricity 
equal to that of a powerful thunder-storm." These passages occur in series vii. 
p. 250 — 7 ; and they suffice to convey " an almost overwhelming idea of the 
extraordinary quantity or degree of electric power which naturally belongs to the 
particles of matter." 
We have thus slightly glanced at the chemical, or rather electrical, elements of 
vegetables and plants ; not with any object to introduce chemical discussion, but to 
render it manifest that horticulture can never be duly understood or correctly applied 
until its principles be determined. In common with agriculture, it must be 
scientifically investigated by professors duly qualified to analyze and instruct ; and 
the world is deeply indebted to Dr. Justus Liebig for the work just published, 
wherein he has distinctly proved that cultivators are wandering in the dark at the 
very time when means are at command, were they duly applied, to remove 
difficulties and obviate perplexities by the establishment of positive facts. 
The practical gardener, if he duly appreciate the quotation and remarks, will 
see at a glance the reason of his embarrassments and failures : he will also be 
sensible of the wondrous mechanism which he superintends ; he will perceive that 
from the four elements described, all the specific fluids of his plants, their chemical 
and medicinal principles, their sapid and odorous qualities, are derived; and therefore, 
if a plant do not meet with its proper aliment, or rather, if it be exposed to agents 
which disturb the natural assimilations, a morbid action must be induced, and disease 
VOL. VIII. — NO. LXXXVII. I 
