ON THE HIGHEST MAGNIFYING POWEES. 
42^ 
I Lave not referred to tlie use of very high powers in 
studying the cLaracters of tLe Diatomacese, because it is a 
brancL of microscopic investigation wLicL I have very little 
studied. OtLer observers will probably state very shortly if 
anything is gained by the use of these high powers in this. 
department. 
I feel sure that^ by improved means in illuminating 
the objects^ many new and important points will be 
made out by the use of very high magnifying powers. Mr. 
Brooke has already suggested possible improvements in the 
condenser, some of which, I believe, he will carry out shortly; 
and Messrs. Powell & Lealand and several microscopists are 
now working in the same direction. I feel confident that 
many new and highly important facts will yet be demon- 
strated, even in the simplest and best known objects, by- 
improved methods of observation. 
