THE DETECTION AND WIDE DISTRIBUTION OF YTTRIUM. 
917 
solution contained 1 grain of calcium. This operation was performed in a room in 
which had been no yttria compound, and the chemicals and apparatus were new, and 
had not been taken into the general laboratory. A portion of the standard solution 
was precipitated with amnionic oxalate, and the calcic oxalate ignited and treated 
with sulphuric acid. Tested in the radiant matter tube it gave no citron band. 
Pure yttric sulphate was dissolved in water to such a strength that 3,000 grains of 
solution contained 1 grain of yttrium. 
80. The solutions were mixed together in the proportion of 1 of yttrium to 100 
of calcium, evaporated to dryness, and ignited with sulphuric acid, and the residue 
tested in a radiant matter tube. The spectrum was bright, the citron band, the two 
green bands, the blue, and the red bands showed distinctly. 
81. A mixture was now prepared in the proportion of 1 of yttrium to 500 of 
calcium, and tested as above. The citron band was strong, but the green bands were 
fainter; the blue bands were still visible. 
82. A mixture containing 1 of yttrium to 1000 of calcium was next prepared. In 
the radiant matter tube the citron band was almost as strong as in the last experiment, 
but the edges were not so sharp, the blue bands were faint, and the green bands had 
disappeared. 
83. A mixture containing 1 of yttrium to 5000 of calcium tested in the radiant 
matter tube showed the citron band still very bright, but hazy about the edges. No 
other bands were seen. 
84. A mixture of 1 yttrium and 10,000 of calcium was now tried. The citron 
band was still decided, but not at all sharp. 
85. One of yttrium to 100,000 of calcium was next prepared and tested. The 
citron band was faint, but easily seen. It could not, however, be obtained at all 
sharp, and appeared broader than usual. 
86. A mixture of 1 of yttrium and 1,000,000 of calcium was lastly prepared, and 
tested in the radiant matter tube. The citron band was very faint, but there was no 
mistaking its presence, and with care I have no doubt a smaller quantity than 1 in 
1,000,000 could be detected. This, however, appears to be near the limit of the test. 
87. These seven tubes were mounted on a board, so that connexion with the 
induction coil could rapidly be made to either of them ; and various minerals, &c., 
were prepared and tested in radiant matter tubes (10). By comparing their spectra 
with those of the standard tubes I could, after a little practice, determine roughly the 
proportion of yttrium present, supposing the test not to be interfered with by the 
presence of phosphoric acid (78). 
88. The following are some of the most interesting results obtained in this way :— 
6 B 
MDCCCLXXXIII. 
