MODERN METHODS OF SCIENCE. 593 
in the material constitution of all known substances, and recog- 
nizing them as the same whether in the earth or in the sun. 
I would, therefore, caution against too great enthusiasm, for we 
are far more ignorant than we sometimes suppose. In fact, true 
philosophy dictates to its followers humility, and that it is the 
province of ignorance to believe that it knows everything, while 
the philosopher is aware that he knows little or nothing. 
While we are prying into space, and studying the matter, size, 
and movements of the heavenly bodies far beyond our own uni- 
verse, we leave behind us a vast number of things that have baffled 
our scrutiny and defied both science and metaphysics. When we 
look at our bodies, without reference to the consciousness that is 
within, but merely studying what relates to our physical parts, 
how many things concerning it we have not discovered ! 
While occupied, the early part of this year, in reflecting upon the 
conservation of force and certain meteoric phenomena connected 
with the sun, my attention was frequently drawn to the small- 
pox that was then in the form of a violent epidemic around me. 
Seeing persons being vaccinated who had in their childhood 
been subjected to the same operation, and observing in the vast 
majority of cases the failure of the production of any effect, I 
asked myself the question: How are we to rank that mysterious 
agent which, when brought to bear upon the system, in however 
minute a quantity, not only permeates every fibre and cell in every 
part of the body, but is never lost? for when through years every 
particle of the body (with perhaps the exception of the teeth and 
a part of the bones) has been renewed over and over again, yet, 
as each particle gave place to a new one, this vaccine energy (if I 
may so call it) was imparted to the new matter, and so on through 
life. Here then was the conservation of a force as mysterious in 
its course and operation, and as hard to be understood, as that of 
Motion, light, or any other of the recognized forms of the energies 
of matter. 
Yes! after we have studied the heavens and all contained 
therein that the aided eye can reach, we shall yet have to de- 
scend to earth and study the every-day physical phenomena that 
are in and around men, finding even greater mysteries to unravel 
that meet our unaided senses every moment of our existence. 
I come now to the last point to which I wish to call the atten- 
tion of the members of the association in the pursuit of their in- 
` AMER. NATURALIST, VOL. VII. 38 
