ADDBESS. 
XXXIX 
Exact knowledge of the nature of the retina, of the vitreous and crystal’ 
line humours, and of other delicate constituents of tlie organ of vision_the 
most wonderful of all the organs with whicli God has entrusted man_has 
been remarkably advanced by the skilful use of the improved microscojKrs 
of the present day. I rejoice that, among the proposed arrangements ol' the 
Association at its present meeting, one evening, Tuesday the iflth of J une, will 
be specially devoted to an exhibition of microscopic objects. The beautiful 
discoveries of Sir David Brewster (whom, in this Associatiuu, we must always 
mention as one of our earliest friends and patrons, three time* one of our 
Vice-Presidents,) have been carefully confirmed ; and many interesting va¬ 
rieties have beeri noticed in the structure of the crystalline lens of tluj eye* 
of different species of animals. 
The most brilliant result, perhaps, of microscopic anatomical research has 
been the actual observation of the iraimii of the blood from the arteries to 
the veins; the last fact required—it; indeed, such an expression be allow- 
ST proof of Harvey’s doctrine of the circulation of the blood. 
Malpighi first observed the transit in the large capillaries of the frog’s web. 
It has since been observed in most other tissues, and in many other animaU. 
No part of the animal body has been the subject of more, or of more suc- 
wssful, researches than the blood itself. The forms and dimensions and 
diversities of structure characteristic of the coloured discs, corpuscles, or 
blood-globules, as they were once termed, in the different classes, orders, and 
genera of animals, have been described, and for the most jiart accurately de¬ 
picted ; and, through the concurrence of numeroua observers, the anatomical 
knowledge of these minute particles, invisible to the naked eye. lias become 
as exact and precise as the knowledge of the blood-vessels themselves, or of 
any other of the grosser and more conspicuous systems of organs; and ha# 
added,—when wc consider how easily tlie action is tleraiiged, by how many 
causes Jt^ay be diseased or stopped,—another to the many proofs that wc 
are fearfully as well as wonderfully made. In surveying how our frame is 
ornied, how sustained, how revived by sleep, one of the most nnndroui of 
a the incidents of our nature, what sufiering is produced by any pressure 
on the lungs, and yet how uncoiisoioosly we breathe a million times in health 
or one in sickness,—I cannot hut feel that our Heavenly Failu-r gave an¬ 
other proof of His essential character, when, in answer to the prayer of 
• OSes, “Show me 1 hy Glory,” God answered, “ I will vaixsc alimu goodness 
to pass before thee." 
In no department of science has the confluence of its cultivator#— at such 
annual meetings as the present—been more influential in advancing its pro¬ 
gress m the right direction than in Systematic Naturae Histort. 
ystematic Natural History is pre-eminently the .science of observation ; 
cience made up of insulated facts and phajiiomena collected from the earth, 
e air, and the waters,—first, carefully ub-served, and then distributed or gene¬ 
ra uedaccording to resemblances and analogies. Every fact, ifii be deserving 
sue 1 a description,—that i# to gay, if it be truly observed ami accurately 
8 ted—is welcome to the man of science, though the obseiver himself may 
not be in a condition to recognise the full signification of hi# own fact, or iu 
earings on collateral plieeooniena. But if this be the case when one fact is 
conimunicated to one man of science, such particulars, when communicated to 
an Association like the present, and discussed in their appropriate Section of 
scientific observers, speedily gain their right place and do tlieir duty in the 
steady advancemeut of natural science. The observer thus, for ilie first time, 
made cognizant of the full value and importance of his own observation, 
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