centuries have not rung off its terrors! The ejaculation, "God bless you," when a person sneezes, can, it is said, be traced to the comet of the year 590. It was universally believed that the comet caused the epidemic of that year. The most marked character of the disease was the fit of sneezing, in which the patient frequently died. When the bystanders heard a sneeze, they bestowed their benedictions by exclaiming, "God bless you." And through the long centuries following, this custom has been kept up.
The Abbé Zantédeschi of Padua has recently contrived some experiments which strikingly illustrate the constitution of comets, and also, as he thinks, that of the corona of solar eclipses. His opinion is, and it is shared by M. Faye and Father Secchi of Rome, that the moon has an atmosphere of considerable height, and that the corona is simply this atmosphere illuminated by the sun hid behind the moon. The atmosphere is not gaseous like ours, but is composed of highly attenuated particles of matter derived from the surface of the moon. Such an atmosphere would not refract light, so as to be detected by the occultation of stars; but it would reflect light in such a way as to be made visible in total eclipses. The above physicists are therefore opposed to the general opinion that the corona belongs to the sun, and not to the moon. Zantédeschi, by using very fine dust to represent the lunar atmo-
