154 ON THE CHOICE OF A MICROSCOPE. 
Carpenter’s great work, ‘The Microscope and its Revela- 
tions,’ is, in fact, a complete Cyclopzdia of itself, in which 
the above subjects are most ably and fully discussed. The 
choice, therefore, of a microscope, about which so much has 
been, and we may safely add is being written, which has 
become so important an instrument in the hands of the 
medical student and physiologist, and which opens to the 
general observer the secrets of minute Nature with a clear- 
ness and ease till of late unexampled—the choice at the 
outset of the most efficient instrument that can be procured 
by the lover of microscopic research according to his means 
and requirements is a point of some consequence, and about 
which I propose now to say a few words. And in doing 
this, I am merely going to give my own experience in the 
matter, with such positive and direct advice as may help to 
guide the inexperienced purchaser in his choice. And firstly, 
my observations shall be addressed to those who can afford 
to possess themselves of the most perfect and expensive 
instruments. I would say, then, to such, what I shall pro- 
bably have occasion to repeat more than once—Begin by 
procuring the best microscope stand that the best optician can 
give you. To explain the optical principles and somewhat 
complicated mechanism of the compound achromatic mi- 
croscope with such books as Dr. Carpenter’s, and Mr. 
Quekett’s, and others before the public, would be altogether 
superfluous in a little paper like the present. Nor is it 
necessary to enter into the details of its elementary con- 
struction, now that illustrated catalogues within the reach of 
all are issued by some of our first opticians, with all the 
various parts figured and described. Besides, it may be 
taken for granted that a person about to invest a large sum 
in the purchase of a microscope has a general notion of its 
form and build. He may fairly be supposed to know the eye- 
piece from the object-glass, why they are so called, and that 
on the union of both depends the magnifying power. He 
may be supposed to know that the stand of the microscope 
in Insects,” ‘Trans. Linn. Soe.’ vol. 28, p. 189; and Mr. Tuffen West’s 
“Memoir on the Foot of a Fly,” ‘ Trans. Linn. Soc.’ vol. 22, p. 393; also 
M. Bernard Deschamps on ‘‘ The Organization of the Wings of Lepidop- 
terous Insects,” ‘Ann. Nat. Science,’ 2nd Zoolog. Series, vol. iii, p. 111; 
and Mr. R. Beck, on ‘‘The Podurn Scale,” ‘Trans. Micr. Soc.’ N.S. vol. x, 
1862, p. 838. See again Dr. Bowerbank, Mr. Huxley, Mr. Rainey, and 
Professor Williamson’s ‘Treatises on Sponges’ and the ‘ Structure of Shells.’ 
And lastly Mr. Henfrey on ‘The Development of Pollen-grains,” in the 
‘Micrographiec Dictionary,’ second edition, p. 558. The above three classes 
of objects will be sufficient to give some idea of the wide field over which 
others extend, and those yet unexplored. 
