REPORT ON CHEMISTRY. 
451 
He found liquid euchlorine to have a density of 1*4 to 1*5, 
protoxide of chlorine 1*5, sulphuretted hydrogen 06, carbonic 
acid 0*6 to 0*7. Mr. Kemp has found liquid sulphurous acid a 
conductor, liquid chlorine and cyanogen non-conductors of elec¬ 
tricity. 
Law of Mariotte ,—A question of great importance has lately 
been raised regarding the law of Mariotte. From the experi¬ 
ments of Oersted in 1825, it appeared that sulphurous acid gas 
showed a deviation from the law, diminishing in volume, under 
increased pressure, more rapidly than common air. Thus, 
their volumes were equal at the following pressures. 
Air. 
Gas. 
Air. 
Gas. 
1 
1 
2-8207 
2-7819 
1*0229 
1-1215 
2*9556 
2*9057 
1-1750 
1*1729 
3*0974 
3*0407 
1*3644 
1-3634 
3-31S6 
3-1889 
This difference was attributed by Oersted to an incipient 
condensation. Despretz has more lately made * some experi¬ 
ments on sulphurous acid, sulphuretted hydrogen, cyanogen, 
and ammonia; in which he confirms the observation of Oersted, 
and renders it probable that the unequal march of the conden¬ 
sible gases, under increasing pressures, is due to some law of 
their constitution. He gives for ammonia and common air the 
following numbers: 
Ammonia. Air. 
1- 819.1-85 
2- 582.2-663 
3- 863 . 4-132 
denoting the pressures under which the volumes remain equal. 
If these gases, then, diminish in volume more rapidly than 
common air under increasing , they should also expand more 
rapidly under decreasing pressures; and there is no reason for 
believing that the pressure of the atmosphere constitutes a fixed 
point, at which the volumes of all gases accord with theory, and 
from which the deviations in contracting or expanding com¬ 
mence. We may therefore find in this fact a probable cause 
why the specific gravities of the condensible gases is generally 
obtained higher by experiment than by theory it ought to be. 
* Annates de Chimie, xxxiv. pp. 335, 443. 
2 f 2 
