Condition of Microscopy in England. By Franh Crisp. 125 
was as ready to liis hand as it was to that of Hall ; and even after 
achromatism had been established, Biot (no mean authority) 
declared that it would be “ impossible ” to work achromatic object- 
glasses for the microscope on account of their diminutive size. 
It is both amusing and instructive to take books written at 
different periods of the present century, and note how each writer 
in his turn expresses the conviction that now at last perfection has 
been reached. Thus Sir D. Brewster, in 1813, wrote that, “ in 
the combination of single lenses to form the compound microscope, 
opticians have arrived at a great degree of perfection.” In 1829, 
after the first achromatic object-glass had been successfully made, 
Dr. Goring wrote that “ microscopes are now placed completely on a 
level with telescopes, and like them must remain stationary in their 
construction.” Sir D. Brewster, later, wrote : “ The ingenuity of 
philosophers and of artists has been nearly exhausted in devising 
the best forms of object-glasses and of eye-glasses for the compound 
microscope.” What was written so lately as 1875 I have already 
referred to. 
I believe that we are far from having arrived at the limits of 
the possible ; but whether this view is accepted or not, I may, I 
think, assume that, however high may be the authority on which 
such a statement as that which 1 have referred to is made, there can 
be no necessity to spend any time in proving that much is still to 
be learnt — that we all agree in the definition given of the character 
of the true philosopher, “ hoping all things not impossible, and 
believing all things not unreasonable,” and “ are ready to encourage 
rather than to suppress anything that can offer a prospect or a 
hope beyond the present obscure and unsatisfactory state.” 
What, in my view, is desirable is not that the Society should 
value less highly than they do now investigations in the various 
branches of natural science that can be made only by the aid of 
the microscope, nor that we should in the smallest degree diminish 
the appreciation which we have of those Fellows who bring the 
results of such investigations before us ; but simply that more 
attention and encouragement than are given at present should be 
given by the Society collectively, and by the Fellows individually, 
to what I may call the subject of pure microscopy, which may he 
considered as standing in much the same relation to what is now 
accepted as “microscopy,” as pure mathematics stands to applied 
mathematics (so called). 
The optical principles of the microscope and its accessories 
form one branch, the other deals with the investigation (considered 
mainly as a problem of mathematics and physics) of the phenomena 
presented by objects viewed by means of the microscope, and the 
determination of their real properties, notwithstanding their de- 
ceptive visual appearances. 
