of Gases from Meteorie Iron. 299 
the first carbon band was now visible, and the others were 
stronger. There could be no question as to the evolution of 
both “hydrogen and the carbon gases, without the application 
of heat, by simple diminution of the atmospheric pressure. 
A very gentle heat was appnon: to the tube for a few minutes, 
making it hardly warm enough to give pain when touched by 
the hand. This had the effect to raise the gauge to 28 mm. 
in fifteen minutes, and cause an entire change in the appearance 
of the vacuum-tube, which became greenish in the broad part, 
like those in the former experiments. The spectrum, when the 
pressure was reduced to a few millimeters, showed the carbon 
bands quite bright, and as the pressure decreased the first one 
became clearly resolved into five fine lines nearly equidistant, 
upon a faintly luminous background. 
A somewhat stronger heat was now brought to bear upon 
the tube, but far less than would have been necessary to brin 
it to redness, as it was desired to avoid the possibility of error 
from the oxidation of the carbon by traces of oxygen left in 
the tube. The gauge rose to 50 mm., sinking to 47 mm. as 
the tube regained its ordinary oe doubtless from the 
contraction of the gas on cooling; for, on subsequently ex- 
hausting, it was found that the gauge pe sa a rise, though 
with extreme slowness The spectr rum did not differ essen- 
tially from that before observed, except in the freate intensit v 
of the carbon bands. <A few cubi ic centimeters of the gas, co 
lected during the second ie when tested quail 
gave evidence of the presence of hydrogen, carbonic oxi 
carbonic di-oxide. “Th he proportion of the latter did not a pear 
e more than three or four ti er cent, that of the carbonic 
oxide lg probably a isl 
like that o eee. The tube was subsequently heated to 
scarcely perceptible. Enough gas was seh off He raise the 
timeters, and was solid. The seat overed with nish 
The examination was made in the sam nett as in the pre- 
vious cases, excepting that the Baas remained jane er. 
Zhauston, When the tension w 
mm. the red a n hydrogen ae were brilliant, ssh she, 
carbon Breer appeared, a i: sets ie as the rarefaetion 
ie Jour Ser. Turrn § Srniss—Vor. TX, No. 82.— 
