1902} MICROSCOPICAL JOURNAL. 17 
denser having a power of 4-10 inch, and a numerical aper- 
ture of ‘99, whichis practically totally aplanatic. This 
will be found a great auxiliary to the range of condensers, 
especially as it possesses a sufficiently large field-lens, 
and is not so bulky in the mounting as to obstruct the 
moving plates of the mechanical stage. There is quite a 
comfort in using a condenser of this power with objectives 
of low and medium magnification. 
OpJEcT MARKER.—A very neat accessory, and one that 
is frequently required, is a means of indicating by a mark 
on the specimen cover exactly where a particular struc- 
ture that has been observed can be found again. Leitz 
makes such a fitting which replaces the objective after 
the required portion of the object has been found. The 
front portion of the marker is then brought into contact 
with the object,anda mark is made upon it which in- 
dicates for the future the position of the particular struc- 
ture. Its cost is very small. 
Notes on Microscopy. 
F. SHILLINGTON SCALES, F. R. M. S. 
QuEKETT MicroscopicaL CLus.—The 389th ordinary 
meeting of the club and first of Session 1901-1902 was 
held on Friday evening, October 18th, at 20 Hanover 
Square, W., Mr. J. G@. Waller, F.S. A., Vice-President, 
in the chair. New members were balloted for. The 
Secretary read a list of books and periodicals added to the 
library since the last meeting. The additions to the . 
cabinet were announced and acknowledged. These last 
included some slides of plague bacillus found or cultivat- 
ed under various conditions mounted and presented by 
Mr. Pound, of the Stock Institute at Brisbane. Mr. 
Scourfield read a paper by Mr, A. Ashe on ‘“Two-speed 
Fine Adjustments.” This was a description of several 
forms of fine adjustment, having two milled heads rotat- 
