58 The American Geologist. January, i90i. 
"In fluorescent substances excitation produces a certain opalescence 
or milkiness which is sometimes of sufficient strength to be of import- 
ance. It cannot be taken as an indication of impurities in the materials. 
In the white diamond such a phenomenon is a detrimental quality. 
"Fluorescence affords a simple and positive method of distinguishing 
some of the fluorescent gems from imitations. Glass is not fluorescent 
and hence is easily detected. Other compositions when fluorescent show 
diff^erent colors from the genuine stones. In doublets the cement ap- 
pears as an opaque film and the components differ in behavior. Arti- 
ficial pearls of high grade have not been examined, but probably they 
will behave like the genuine. Artificial, or 'regenerated,' ruby has been 
examined in a single specimen. It acts like the natural stone in blue 
light, while with the air-gap spark between iron or aluminum electrodes 
it has a brighter color than any of fhe several natural rubies which 
were examined." 
The following gems were stated to be non-fluorescent : garnet, ame- 
thyst, Spanish topaz, yellow Brazilian topaz, sapphire, ordinary berj-l, 
possibly Siamese ruby. e. o. hovey. Secretary. 
SUESS' REMARKS AT THE CLOSING BANQUET OF THE NiNTH INTER- 
NATIONAL Geological Congress. The closing banquet of the Congress 
at Vienna was one of those pleasant affairs which will live long in the 
memory of the attending geologists because of the general good fellow- 
ship. Tietze, as president of the Congress, presided at this banquet and 
spoke the official farewell in French, followed by Geikie with reminis- 
cences in English. The latter told us that more than forty years ago 
he made his first visit to Vienna for the purpose of consulting with 
one of the great geologists of that day. Of those he then met, nearly 
all are now gone excepting Suess, then a young man beginning to at- 
tract attention, but since become known to us all through his masterly 
work "Das Antlitz der Erde." 
This reference to forty years ago when both Geikie and Suess were 
young, visibly affected the latter. Towards the end of the speaking, 
Suess rose and with bowed head and a low voice increasing to consider- 
able volume as he proceeded, spoke eloquently in German the following: 
"My distinguished, master. Sir Archibald Geikie, xvas so kind as to 
say that more than forty years ago he became personally acquainted 
with me. With my highly honored friend Baron Richthofen, it is rath- 
er near fifty years. What a memorable half centurj^ we have lived 
through ! During this time, under the influence of increasing knowl- 
edge of nature, all human conceptions of the earth have changed. It is 
remarkable, however, to see how often the single inquirer, bent upon 
the object of his quest, fails to comprehend the broader aspects of a 
problem by whose details he is fettered, just as the stone-cutter clinging 
to the fagade, cannot see the splendor of the structure on which he 
himself is engaged. And yet there is a special charm in geological 
studies precisely on account of the extraordinarj- range of accommo- 
dation that is demanded of the eye, of the same eye which now ex- 
amines the disintegration of quartz in a thin slide under the microscope. 
