The Daily bulletin. [volume] (Honolulu [Hawaii]) 1882-1895, 1886-10-29
CONCERNING MICROSCOPES.

UuNGEhNiN6 WIGnuoUurEo'
EDITOR BULLETIN Il notice on
the fourth page of yesterdays Bull
IETIN, an account of the discovery
of new kind of glass possessing
very superior and remarkable quail
ties for the manufacture of micros-
copic lenses. The alleged fact is in
itself by no means improbable, and
if true, will be source of rejoicing to
all persons who have occasion to
make microscopic Investigations.
The article in question, however,
contains some statements which, to
put it mildly, are incredible, and
others which will be at once recog-
nized as untrue, by any one who has
had any experience in the use of the
microscope or any knowledge of the
laws of optical science.
For instance, we are told that
'The difference between the new
and the old glass consists in the re-
fraction of light" Now we all know
that the magnifying property of
lenses depends primarily upon their
power of refracting light; and the
discovery of glass possessing
superior refracting power to that
now in use is quite credible and
would be very desirable. But that
by simply substituting glass of SUI
perior refraction, the magnifying
power of a microscope can be raised
from five hundred to over two mil
lions, or in other words increased
more than f'oa" hundred thousand
times, is a statement worthy of the
great Munchausen himself. More
over the assertion that "With the
old glass, the full power of the
microscope was the discernment of
the 500th part of an inch," is not
only incorrect, but so grotesquely
untrue that it would be laughed at
by any one who has ever owned or
used microscope of even respect
able power.
/ myself have microscope which
will do vastly more than that, and
there are several parties right here
in Honolulu who have instruments
more powerful than my own. The
red globules of the human blood
one of the commonest objects eX
hibited under microscopes used fol
ordinary clinical Investigations, are
from the 3,000th to the 3,500tl
of an inch in diameter, and th'
blood globules of some quadrupeds
are much smaller than this, those o
the Java musk deer being by actua
measurement rather less than th,
12,00Oth of an inch. The variou
kinds of bacteria which are just no,
receiving so much attention fror
physicians and biologists, and whic
can be not only seen, but accuratel
measured and studied under tn
microscopes now in use, are man
times smaller than the limit assigne
in the article referred to.
High magnifying power is by n
means the only, nor always the mos
valuable quality in a good micros
cope. The qualities known as def
milton and penetration are some
times even more important, so muc
so that lens of comparatively To-
magnifying but of superior deiinin
and penetrating power, is often {
more practical value to the invest
gator than one which magnitit
much more, but is deficient in thes
particulars. II is in the line of in
proyements in these respects rathC
than in increasing the mere pow'
to enlarge objects, that the create
Improvements have been made {
late years. There are also certai
practical difficulties in microscop
workrwhich are not appreciated {
understood by those who have /
personal knowledge of such worl
and who regard microscope simpl
as an instrument for increasing I'll
apparent size of minute object
These difficulties increase ver
rapidly as we attempt to use vel
high magnifying powers, and ten
TO put limit TO our possibilities
that direction.
The only difficulty will he
mention is that of illumination.
precisely the proportion that v
magnify an object, we at the san
time diminish the light. If for il
stance we magnify an object IL
Tooth of an inch square until it al
pears to the eye to be one inc
square, we are said to magnify
one hundred diameters, but we ha,