4 
252 ; ? MICROSCOPY. 
the required distance. This method is applicable to the lose 
powers, and is for them far preferable to the usual procedure of 7 
guessing at the amount of correction required and taking a series — 7 
of photographs to determine which is the most successful correc- ; 
tion. a: 
A SPHERICAL Diiia usies to use tubular diaphragaal 2 
with my microscope, and knowing how clumsy the ordinary ones’ — 
are, I set to work, and endeavored to devise a substitute. I made 
a globe one and one-fourth inches in diameter and drilled holes 
through it of the proper grade of sizes, and adjusted it so that bya — 
spring stop the holes will correspond tothe axis of the microscope — 
when the ball is revolved on its axis by a milled head at the right — 
of the stage. The fittings are so arranged that the diaphragm t 
may approach or recede from the stage so as to touch the slide or 
be far from it. The globe may be made hollow and the lower Pa 
cut off if the tubular wells are not desired. I think this form of a 
diaphragm offers many advantages over the ordinary piece of ap- a 
paratus.—F. B. KIMBALL. l | 
and cutting slices through both carrot and leaf. The sections a 
then soaked in water in a watch-glass under an exhausted t 
ceiver, stained with hematoxylin, and transferred through water, 
absolute alcohol and oil of cloves to the mounting medium. In 
the oil of cloves they would curl up were they not prevented bya 
heavy cover glass laid upon them. 
ANOTHER Erecror.—John A. Perry, of Liverpool, recomme 
an objective, inverted, above the ey¢-piece as an erector. Wi 
1 inch working objective and A-ocular, a } or 4 objective aan 
inverted and stood upon the cap of the oe.. giving an incr 
of power and of working distance as well as an erect image. : 
4 objective supported on an adapter two inches long seems to | 
form as well as any; but the inconveniences of the method $i 
to be too great for its advantages, J 
; _ Cemexrs. —Mr, F Kitton prefers, for making varnish 
: : with the addition of a small quantity of gold size; 
cells when Sela Eien sige over graki in a cool ovem. 
