ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
643 
MICKOSCOPY. 
[The Publication Committee of the Journal has decided on resuming the issue 
of the Microscopic Bibliography, which was dropped on the lamented death of 
Mr. John Mayall, jun. It is intended in future to give at least the title of 
every work or paper (commencing from January 1st, 1899) coming under the 
head of Microscopy A or of Technique 3 (Microtomes) ; and we shall be much 
obliged to any of our Fellows who will call our attention to any such papers or 
articles published in Journals which are likely to escape our notice. — Editor.] 
A. Instruments, Accessories, &c.* 
(1) Stands. 
Three Small Hand-Microscopes. — A case containing three Micro- 
scopes was exhibited at the meeting of the Society on Nov. 15th, by 
Mr. Edward Swan, one of which is represented in fig. 149. The following 
account of them was given by the President. 
“ They are interesting from several points of view. First, it will be 
noticed that although they are of archaic type, they are of comparatively 
modern manufacture. This kind of Microscope was first designed by 
Leeuwenhoek about 1673, but his screw focussing arrangement was of a 
very crude construction. In 1702 we find a considerable improvement 
Fig. 149. 
effected by Musschenbroek and Wilson. The highest pitch to which 
these instruments arrived can be well seen in the extract from Ledei- 
miiller’s work.f This last instrument was called a ‘ Compass ’ Micro- 
scope, because the lens was mounted on one leg of a ‘ spring divider * 
compass, the object being placed on the other leg, and focussing adjust- 
ment being performed by means of the screw which worked the spring 
divider ; this, in short, was the principle underlying all the above-men- 
tioned instruments, as well as those now on the table. 
“ As some of Lieberkuhn’s improvements are incorporated in the 
‘ Compass * Microscope, its date could not be earlier than 1745, nor 
later than the publication of Ledermiiller’s book in 1763. Now, to 
return to the three Microscopes on the table, as they are fitted with 
Coddington lenses, they cannot have been made earlier than 1830, but 
from the appearance of their workmanship they may be dated as late as 
1860. 
“ The history of the Coddington lens is also of interest ; for Cod- 
* This subdivision contains (1) Stands; (2) Eye-pieces and Objectives; (3) Illu- 
minating and other Apparatus ; (4) Photomicrography ; (5) Microscopical Optics 
and Manipulation ; (6) Miscellaneous. t Cf. this Journal, ante, p. 529. 
