184 
CORRESPONDENCE. 
they did in the first instance, and thus refinishing, which all micro- 
scopists have to do sometimes, becomes an operation of the greatest 
ease. 
As the matter now stands, measuring with a rule is more trouble 
than most persons are willing to take ; and so, microscopists usually 
trust to the eye for centering their specimens. As a consequence, 
those prepared by even some of the most celebrated workers are often 
as much as an eighth of an inch away from a true centre. This is 
not merely a defect, artistically, but is a source - of considerable 
annoyance in many ways, practically. 
Believing that my invention will prove to be of no little value to 
the great body of microscopical workers, I trust that you will allow 
me to present it to them, through the medium of your excellent 
J ournal. 
Bespectfully yours, 
C. F. Cox. 
Loan Collection of Scientific Instruments and Microscopy. 
To the Editor of the ' Monthly Microscopical Journal.' 
February 20, 1875. 
Sir, — Can you tell me why, at the meeting at South Kensington 
on Saturday, the Eoyal Microscopical Society was totally unrepre- 
sented ? Surely the Society has not declined a position on a body 
which has to do with " discussing the advisability of bringing to- 
gether a loan collection of scientific apparatus " ? If so, I should like 
to know the reason ; for it seems to me that the Microscopical Society 
has in its collection the finest illustrations of the progress made in 
the optical construction of the microscope, from the time of Leuwen- 
hoek to that of Wenham, that the world possesses. It does seem 
strange, then, that a meeting which included representatives of 
every other possible branch of physical, natural, and applied science, 
should nevertheless have had no member who in the slightest degree 
" stood up " for microscopy par excellence. 
I am. Sir, yours, &c.. 
Camera Luoida. 
