ARGON

a gaseous substance in the earth’s atmosphere first isolated in 1894 by Lord Rayleigh and Prof. W. Ramsay, after a long series of experiments. Its chemical properties have not yet been ascertained, and it seems to have no chemical affinity of any kind. It forms 0.933 of one per cent by volume of the air and its density is twenty times that of hydrogen. It has been liquified and solidified. Its critical temperature “4 179° below zero, Fahrenheit, and ai 309° below zero, Fahrenheit, it Rie,