NEW MICROSCOPES—-SEIDEL AND WINTER 207 
that it does for visible light. Staining of specimens is thus unneces- 
sary, making it possible to secure photomicrographs of living minute 
organisms. 
In addition to these four microscopes, a fourth, belonging to the 
Canadian Department of Mines and located at Ottawa, and almost 
identical in principle and construction to that of Drs. Dane and 
Graton, has demonstrated ability to attain equally high resolution. 
This, like the scopes of Drs. Dane, Graton, and Lucas, is fitted 
with a tube for visual observation although intended mainly for 
microphotographical work in the field of metallurgy. It is Dr. 
Graton’s belief, however, that his instrument and that of Dr. Dane 
might also be adaptable to the purposes of biological research. Re- 
ferring, in the description of their “Precision, All Purpose Micro- 
camera” (Journ. Opt. Soc. Amer.), to the necessity or “desirability” of 
“reéxamining the classical conception of the limit of useful magnifi- 
cation,” Drs. Dane and Graton have this to say: 
So long as the makers accepted the conventional limit as valid and had already 
attained it, there was little incentive toward progress. But with that limit 
apparently surpassed, there is no present knowledge as to how far ahead the 
true limit may lie. If present-day objectives do substantially better than the 
“limit” for which they were designed, is it not reasonable to suppose that effort 
to do better stil] may conceivably be rewarded? 
To such an inquiry there can be but one logical answer—an agree- 
ment which, while perhaps not concurred in by all, must, for those 
stimulated to more intense interest and effort by the possibilities of 
uncovering new facts, pose further questions; for, if the improvement 
of one part results in the improved performance of the whole, is it not 
also reasonable to suppose that additional changes of additional parts, 
yes, even changes with respect to principle and method might likewise 
bear fruit ? 
THE UNIVERSAL MICROSCOPE 
It is not only a reasonable supposition, but already, in one instance, 
a very successful and highly commendable achievement on the part of 
Dr. Royal Raymond Rife of San Diego, Calif., who, for many years, 
has built and worked with light microscopes which far surpass the 
theoretical limitations of the ordinary variety of instrument, all the 
Rife scopes possessing superior ability to attain high magnification 
with accompanying high resolution. The largest and most powerful 
of these, the universal microscope, developed in 1933, consists of 5,682 
parts and is so called because of its adaptability in all fields of miero- 
scopical work, being fully equipped with separate substage condenser 
units for transmitted and monochromatic beam, dark-field, polarized, 
and slit-ultra illumination, including also a special device for crystal- 
lography. ‘The entire optical system of lenses and prisms as well as 
