HALL OF FAME FOR AGASSIZ AND MORSE
The Hall of Fame for Great Americans, located on the campus of New York University, was visited on Thursday, May 10, by thousands of people from many different states and cities, who witnessed the unveiling of the busts of five great Americans.
The men honored with busts this year were Louis Agassiz, Rufus Choate, John Paul Jones, Samuel Finley, Breese Morse, and John Greenleaf Whittier.
RAYS SHOW TOOTH CAVITIES
Teeth, shining like jewels in the dark under the invisible rays of ultraviolet light, reveal by dark spots the places where cavities are beginning to develop, before they become visible to ordinary inspection. If the technique of this kind of examination can be sufficiently perfected, we may expect dentists’ offices to be equipped with the largest types of ultraviolet lamps, to enable up-to-date practitioners to catch cavities before they happen, and so perhaps prevent them.
This possibility is an outgrowth of experiments by Dr. H.C. Benedict, of Northwestern University Dental School, on the fluorescence of teeth under ultraviolet radiation. Like many other substances, human teeth react to these invisible rays by shining brightly with a visible light. This phenomenon is known as fluorescence.
The white spot that marks the beginning of cavity-forming troubles, Dr. Benedict found, does not fluoresce even though no coloring matter has begun to form on it. This seems to be associated with the removal of a thin protective film, for it was found that a similar effect could be obtained by treating a paraffin-coated tooth with acid. Wherever the paraffin had been scratched through, the tooth failed to fluoresce.
SUN A PULSATING STAR
By Gabriella Armellini
From time to time, spots are visible on the sun and they are sometimes so large as to be seen by the naked eye, with the protection, of course, of smoked glass. When examined through powerful telescopes, these spots appear as holes or fissures in the luminous surface.
Statistics have shown that the sun’s surface appears to have the largest number of spots once in every eleven years, after which period a gradual decrease in the number, frequency, and size of the spots is noted. At present, the spots are almost at their maximum.
It has now been ascertained, at the Astronomical Observatory of Rome, situated on the Capitol, that the diameter of the sun varies in proportion with the number and frequency of the spots.