GARDENING AS A SCIENCE. 
251 
Let, therefore, the sons of science coalesce, and instead of jarring, exert their 
utmost powers to honour one another, and to extend the circle of general utility. 
The estahlishment of scientific colleges, or educational schools, wherein the prin- 
ciples of agriculture and gardening shall be investigated, taught, and practised, 
would be a mighty engine in the great work — and we hail the dawn of promise. 
Finally, we appeal to one more extract from the work of the excellent and 
defamed German philosopher, Liebig : it is of more worth than all the fictions 
that have been written to his disparagement. He says : — 
" It is too much forgotten by physiologists that their duty really is, not to 
refute the experiments of others, nor to show that they are erroneous, but to 
discover truth, and that alone. It is startling wlien we reflect that all the time 
and energy of a multitude of persons of genius, talent, and knowledge, are 
€xpended in endeavours to demonstrate each other's errors." 
We rejoice to perceive that this able pen is at work again : a new publication 
is just announced. 
Several years since, a Treatise on Vegetable Physiology was published by the 
Society for the Diffusion of Useful Knowledge, wherein the writer recommended 
the use of a corrosive acid, to detect the position of the vessels and fibres of 
vegetable structure. " If we wish," he said, " to examine the component parts 
of a plant, the portion containing them should be plunged in nitric acid^ and the 
phial placed in boiling water ^ which must be kept at the boiling point for twelve 
or fifteen minutes." 
Never were there directions more vague, unsatisfactory — and, to the chemical 
student, more unworthy of credit. We combated the fallacy at the time, 
because we had proved that by the use of aquafortis, the vegetable tissue must 
be inevitably broken up and destroyed. Even at the present day, when the 
operation of chemical agents is far more extensively understood, it will not be 
irrelevant to retrace a few of the observations which, sixteen years ago, had 
warned the tyro in microscopic researches to refrain from, or employ with the 
utmost caution, certain agents whose operation at all times is violent, and inevi- 
tably tends to destroy whatever they in any degree can act upon. 
Let us presume that a small slice of the growing stem of asparagus be 
investigated in order to detect the sap-vessels, air-cells, and fibres with which 
it abounds (the stem of a lily or asphodel would do as well), and placed as directed 
in a phial of nitrous acid, at a boiling heat. What, we ask, would be the result ? 
If the whole tissue were not destroyed — if by bare possibility any tangible atom 
might remain — it would be so imbued with acid that every instrument of dis- 
section, unless made of glass, would be blackened, corroded, and rendered entirely 
useless. The directions made no allusion to the strength or gravity of the acid — 
and we were led to suppose that it was to be employed pure, and in its 
undiluted state. 
Experiments were then resorted to, and, as might be expected, portions of 
