218 THE MICROSCOPICAL NEWS. 
sediment; noted for the fineness of its film, and for its non- 
contractile property. 
OBJECTIVE CHANGERS.—A correspondent writes asking us which 
of the various “‘changers” we recommend, or whether we still have 
preference for the old “ screw.” 
We have tried the various patterns as they have been brought 
out, and to this date have determined to stick to the “ old screw,” 
as although we are often hard pressed for time we have never 
found the so-called instantaneous changers to enable.more work to 
be done, and we have even discarded the double nose-piece in 
ordinary work. ; 
NE Quip NimIs.—Ray tells us that ‘“ Enough is good as a feast,” 
but the editor of the American Microscopical Journal seems to 
regard a modicum as sufficient from the following paragraph 
extracted from page 111 of the June number of the journal. 
“The great fault with most books on mounting seems to be that 
the instructions are given too much in detail.” We cannot agree 
to this statement. We have never seen a single book (not even 
“‘ Practical Microscopy !”) in which the details have been given as 
fully as we should like to see them described. 
Tuames Mup.—An exceedingly valuable paper by Dr. Lionel 
Beale, F.R.S., on “ The Constituents of Thames Mud,” may be 
found in the February (1884) number of the Journal of the Royal 
Microscopical Society. This paper should be studied by all 
chemists who may be interested in water analysis. 
PROCEEDINGS OF PROVINCIAL SOCIETIES.—We wish it to be 
understood that our pages have never been closed to the Transac- 
tions of Local Microscopical Societies. Zhe orthern Microscopist 
was first started to keep a record of the doings of Northern 
Societies, but after a time it was found necessary to reduce the 
list of objects exhibited at each meeting on account of the many 
complaints from our readers. We have always given every facility 
for the publication of papers read before Provincial Societies ; 
most of our contributors have been supplied with free copies, and 
the cost of illustrations has, in no case, fallen upon the authors. 
Perhaps some of our readers will be good enough to disseminate 
this information. 
