MEMORANDA. 79 
a very much larger field, with more light, and yet without 
any sacrifice of defining quality. In using the lower powers 
of the microscope, it is often of much importance to have the 
whole of a large object in view, such as a section of coal, or 
wood, or a section of Echinus spine, &c., this the new eyepiece 
accomplishes most satisfactorily, and with a beautiful flat 
field. For more minute objects, when these consist of great 
diversity of forms, such as shells of Polycistina, or spicula of 
Gorgonia, or sponges, it is equally good, or better. These 
objects, shown by a one inch glass, and under the dark 
ground illumination, and viewed with the “C” Kelner’s 
eyepiece, have thrown all to whom I have shown the sights 
into extacies; the almost illimitable view and the vast 
variety of objects strike the beholder with wonder; and the 
change that is effected when the old form of eyepiece is sub- 
stituted, is very strikingly in favour of the new. It is also 
equally useful with the higher powers. Many of the larger 
and finest forms of Diatomacez cannot be all seen when 
shown by the highest powers, and a deep eyepiece of the old 
form ; but, with the “ Kelner,’ you may magnify an “ Arach- 
noidiscus,” until it appears like a dinner-plate in size, and 
yet be able to see the whole of the object. In conclusion, I 
may say that nearly all the microscopists to whom I have 
shown it have expressed their approval of its merits by procur- 
ing it for themselves.—Josrru Davison, Newcastle-on-Tyne. 
