488 Scientific Intelligence. 
For the purposes of comparison the author determined the wave- 
lengths of the positive lines in oxygen, hydrogen, nitrogen and air, 
employing for this purpose Geissler tubes, the discharge being that 
of a weak inductorium. The spectra of both the narrow and the 
wide portions of the tubes were observed both as regards wave- 
length and intensity of light, and finally the spectrum of rarefied 
the spectra of certain nebule (4=497'5). Finally the broad band 
of gases under different circumstances of temperature and pressure 
being well established.— Pogg. Ann., exlvi, 569. WwW. G” 
4. On the heat of expunsion of solid bodies,—In the cases of & 
number of different solids and also of water, Burr has com ared 
the quantity of heat absorbed in producing expansion wit the 
whole quantity absorbed, or, in other words, with the total specific 
heat. ‘The author sets out with the extremely probable assump- 
P : 
of one cubic centimeter of iron, 1°°374 C., corresponds to @ work 
of 100 kg. X 0°0000481 centimeters, or 4:81 centimeter-gramt 
This quantity of heat is found in units by multiplying the welg 
tJ 
The total work which this quantity of heat is capable of faye 
ing is 42000 gr.-cm, 17 = 49140 centimeter-grams, while : ie 
a é 8 
00000481 coteauie n-y57 071098 0°980 
0:0000951 0-0000515 8-936 0°0949 14 
00001401 00000573 10°301 0°0577 27378 
0°0001791 0:0000466 18°035 0°0324 1°899 
0:0000628 0:0000265 217166 070324 0°920 
mad ; 0000854 11:165 0°0314 5°800 
Glass, ° 00001451 0-0000262 27446 01770 | » 
‘Water at 16°C., 0-0045854 0-0001600 0-999 1°000 3°81 
2 
: 
Oo 
