ON MICROSCOPIC DISCOVERY. 



595 



the bowels of the earth, you may discern not 

 only the woody fibre, its arrangement, and 

 (he disposal and form of the medullary rays, 

 but even the most delicate of the vegetable 

 organs, such as the spiral vessels and the 

 beautiful terminations of those vessels ! These 

 are distinctly discoverable as in the finest pre- 

 parations of a recent plant. And what can 

 be more amusing and instructive than the 

 examinationof the silicified woods, when formed 

 into sections no thicker than the paper of a 

 bank-note? Thus rendered pervious to light, 

 the organic structure of the wood becomes 

 plainly distinguishable. And emanating from 

 this, what can be a more interesting subject 

 than the inquiry into the mode in which the 

 silicifying process has been carried on by 

 which the constituent elements of the inmost 

 and minutest portions are changed whilst 

 their form and situation and colour remain the 

 same ? In investigating also that extinct genus 

 of plants, the Lepidodendra, a similar idea is 

 raised in the mind, as to what must have been 

 the particular state of the earth with respect 

 to atmosphere and temperature at the period 

 of their growth, and what the changes which 

 have since taken place, in order to bring it to 

 its present condition." " In the foregoing 

 remarks on the application of the microscope 

 to botanical purposes, I have given the reader 

 only a general outline ; to enter upon any thing 

 like details, would of necessity extend our in- 

 troductory chapter of this description far be- 

 yond its proper bounds. I may, nevertheless, 

 be permitted to make use of one example by 

 way of illustration. But how shall I select 

 one where the materials suited to construct it 

 are so superabundant, and where they all 

 present so many points of interest ? It will 

 be readily admitted that this is by no means 

 an easy choice. I will limit my observations, 

 however, to a single microscopic slider, and see 

 what instruction is derivable from it. Suppose 

 this slider to contain some sections of a fossil 

 wood ; for instance, three specimens or shavings 

 of such extreme tenuity, that if they were ex- 

 posed, they would be wafted away on the 

 slightest breeze. Let them be weighed, and 

 they will not exceed a grain. Hand them to 

 the chemist, and he can only prove to you 

 that their primary constituents are oxygen, 

 hydrogen, carbon, &c., and in so doing, he will 

 destroy them. What, then, does an inspec- 

 tion of them under the microscope reveal ? It 

 will tell you, in the first place, whether they 

 grew up, like our forest trees, by yearly ad- 

 ditions to the outside of their woody centres, 

 or by internal accessions, like most of the pro- 

 ductions of the tropics. It will tell you 

 whether their leaves were veined or not 

 whether their embryos were dicotyledons or 

 monocotvledons whether the trees from which 



they were cut had branches or not and, if 

 they had, whether these were thick and sturdy, 

 like the boughs of the oak ; or thin and flexible, 

 like the branches of the fir tribe. It will tell 

 you whether the wood might be easily cleft 

 asunder, like deal ; or would sooner break, 

 like beech ; whether it was elastic, like the 

 pine so admirably suited for the masts of 

 ships ; or like the stubborn oak, would rather 

 snap than yield to the wind. These are some 

 of the ordinary properties developed by the 

 microscope. Again, in taking a more minute 

 physiological survey, our information will be 

 by no means less complete. For these same 

 specimens will disclose to us, under the mi- 

 croscope, the form and arrangement of their 

 woody fibres, the disposition of their barks, 

 the beautiful structure of the tubular recep- 

 tacles by which their secretions have been 

 carried on, and their growth promoted. In 

 short, so much will be revealed by them in 

 this manner, that the actual distinction between 

 a wild and a cultivated tree may be, in some 

 cases, clearly traced." 1 



We now proceed to the second branch of 

 our subject, namely, the consideration of the 

 minute formations and phenomena of the 

 Vegetable Kingdom. Here opens a rich field 

 of interesting observation, and the more in- 

 teresting because it embraces an extensive 

 range of objects with which readers in general 

 can claim familiar acquaintance, so far as their 

 features are obvious to the unassisted eye. It 

 would, we venture to say, be difficult to find 

 a person, young or old, who, in his rural walk, 

 has not stopped to look upon the broad and 

 massive foliage of the oak, or rested beneath 

 the shade of its far spreading branches, who 

 has not gathered the wild flowers that em- 

 broidered his sylvan couch, and wondered at 

 theirsurpassing loveliness, or has not lingered 

 with pleasing delight amidst the luxuriant 

 display of vbgetable beauty in the carefully 

 tended flower-garden. And to those who look 

 with admiration on trees, plants, and flowers, 

 as they exhibit themselves to the unaided 

 sight, and in a passing glance, it cannot be 

 uninteresting to know that under these obvious 

 beauties lie concealed formations so exquisite, 

 and mechanical powers so wonderfully con- 

 trived by the great Artificer of nature to pro- 

 duce, sustain, and carry on the vegetable or- 

 ganization, that, wanting a knowledge of 

 these, we can scarcely be said to know any- 

 thing of the vegetable creation. And here 

 again we call Mr Pritchard to our aid : 

 " Vegetable organography," he observes, 

 " upon which the modern botanist depends so 

 much for his systematic arrangement, and 



1 Pritchard's Microscopic Illustrations, New Edition, 

 pp. 21 and 25. 



