148 Chemistry and Chemical Arts. 
Another object was to prove the effect of temperature on the gas. 
Accordingly it was passed through a serpentine tube twenty five feet 
m length, which was maintained at a temperature 8 or 10°C. below 
zero. ‘The light was not in the smallest degree diminished, nor were 
its deposits upon the orifice at all increased. It was ascertained also 
that the deposits were equal, in burning oil gas and that from rosin. 
In order to compare the expense of the two gases, it was found 
that five cubic feet of gas from rosin gave as much light as nine of 
oil gas. : 
Respecting the products of combustion, or the purity of the gases, 
the advantages in favor of gas from rosin are incontestable.—Bbul. 
de la Soc. d’ Encour. pour V Indus. Nat. Pour Fev. et Avril, 1834. 
29. Anew green pigment for Artists —This color was discover- 
ed by M. Pannetier, a painter of eminence who had studied chem- 
istry with the view of preparing colors suitable for staining porcelain. 
Itis prepared with chrome, and possesses a very brilliant, bluish green 
color. When employed in a state of purity, it does not represent 
the beantiful green tints of plants; but nothing is easier than to 
modify its shade by the addition of brilliant yellows, or of Scheele’s 
green which is obtained very yellow. The new color has a good deal 
of body; it spreads easily under the brush; it possesses a more 
intense tone than the copper greens and has not like them the incon- 
venience of running, however little they may be diluted with a viscid 
oil. It has been submited for six years to the action of solar light, 
without having suffered the slightest alteration. It has been vari- 
ously blended with other colors, and a similar trial, though only for 
one year, has been made, but which has been attended with the same 
success. 
Notwithstanding the great number of colors, which painters have 
at their disposal, there is still not enough to fill all the intervals of 
the chromatic scale. With the finest blue and the most beautiful 
green hitherto within their reach, it would im the opinion of M. Mrr- 
EMEE (to whose consideration the subject was referred) still be im- 
possible, to imitate the brilliant bluish green tint of the new pig- 
ment.—Jdem. Mars, 1834. 
30 Improvement in the manufacture of sealing wax.—M. Victor 
RovumestanT, sealing wax maker to the king, is said to have greatly 
improved the quality of this article by new processes, besides. having 
