The Pr'esidenfs Address. 
65 
poles asunder — the improvement of the instrument involving 
the principles of mechanics and optics^ whilst the objects 
observed by it involve the whole of the facts of the niineral_, 
vegetable^ and animal kingdoms which cannot be seen by 
the naked eye — yet when properly regarded you will see that 
it is only the natural connexion between the workman and 
his tools. I do not believe we do well in our scientific socie- 
ties to confine ourselves to one department of science to the 
exclusion of others. All nature is a whole, and he will best 
work at its parts who understands something of the great 
laws that govern the mass. Let me illustrate my position 
by a fact in the history of our instrument. It was at the 
time that our profoundest mathematicians and most expert 
mechanicians v»^ere employed in solving the question of the 
possibility of a working arrangement of compound achroma- 
tic lenses, that a gentleman whom we may boast of as a 
member of this Society, who, neither a professed mathema- 
tician nor a working mechanist, but combining a knowledge of 
both, solved the great problem which has given to the world 
the most perfect instrument it possesses — the compound 
achromatic microscope. Not only did Mr. Joseph Jackson 
Lister perform this great service, but he showed how his in- 
strument might be used, by contributing a valuable paper on 
the lower forms of invertebrate animals to the ^ Philosophical 
Transactions.^ Mr. Lister is the type of the men that it was 
the object of the Microscopical Society to bring together. It 
was felt that some men might pursue the abstract questions 
relating to the laws of light, that others might investigate 
the delicacies of mechanical arrangement, and that others 
might be employed in the observation of minute structures 
and organisms, but unless they were all brought together the 
practical advantages of their knowledge could not be realised. 
It is here, then, we invite the mathematician to test the truth 
of his laws by the aid of our instruments ; it is here that we 
invite the mechanist to bring forward mechanical arrange- 
ments ; and it is here v/e invite the naturalist in order that he 
may become acquainted with the best methods of investiga- 
tion. The microscope is, as it were, a second eye ; and in 
whatever department of inquiry the natural eye fails for 
want of power to see nearer to the object it investigates, 
that is the department of knowledge we cultivate, whether it 
relates to the instrument used to remove this defect, or the 
object it is thought desirable to observe. 
Some of the founders of this Society can recollect the time 
when the microscope was regarded as a toy, when the com- 
pound microscope as an instrument of research had no exist- 
