Tue MIcROSCOPE. 383 
ment, including the milled heads. This makes great weight for 
the fine adjustment to carry, and as a consequence it takes the 
super-excellent skill to which “Amateur” refers to construct 
such an arrangement in a manner that will give that very sensi- 
tive and accurate movement so much desired. If, however, the 
fine adjustment is placed upon the nose-piece it then sustains 
only the weight of the objective, and for that reason it is far 
more steady and delicately responsive to the touch than any 
adjustment which carries so much as one at the back of the arm 
is compelled to do. The plan adopted by Tolles in the con- 
struction of the fine adjustment upon the nose-piece, was par- 
ticularly to support the end of the spindle above the screw and 
the milled head, and with such a construction only ordinarily 
careful workmanship was required to produce a result the excel- 
lence of which would remain after years of wear. The objection 
urged against the adjustment when placed upon the nose-piece, 
that in its operation it changes the length of the body and con- 
sequently the magnifying power, was not by Tolles, I think, con- 
sidered to have any importance, inasmuch as in all his best work 
the nose-piece adjustment was used. 
Yours truly, 
Boston, Mass. F. F. STANLEY. 
Epirtor THE Microscorr :— 
In answer to his query in the February number, D. will find 
a valuable paper containing instructions for mounting insects 
without pressure in the December, 1882, issue of the American 
Monthly Microscopical Journal. A synopsis of the process is as 
follows: 1. Boil in caustic soda solution (1 to 8). 2. Wash 
out soda solution with hot water. 3. Pour off water and replace 
by alcohol. 4. Pour away alcohol and replace by ether. 5. 
Pour off ether, and (a), add alcohol again, and then water, if to 
be mounted in glycerine or aqueous media; or (b), replace the 
ether by turpentine for resinous mounting. Preparation of the 
object is done in a test-tube. For details, the paper should be 
read. 
Benicta, CAu. Epwarp Gray, M. D. 
