1854.] OF THE ROYAL INSTITUTION. 495 
“ soon as the picture is finished, it is syringed over with water-glass. 
“ After the wall is dry, the syringing is continued as long as a wet 
“* sponge can remove any of the colour. An efflorescence of car- 
** bonate of soda sometimes appears on the picture soon after its 
“completion. This may either be removed by syringing with 
“« water, or may be left to the action of the atmosphere.” Not to 
dwell on the obvious advantages possessed by the stereochrome 
over the real fresco, (such as its admitting of being retouched and 
its dispensing with joinings,) it appears that damp and atmospheric 
influences, notoriously destructive of real fresco, do not injure pictures 
executed by this process. 
* The following crucial experiment was made on one of these pic- 
tures. It was suspended for twelve months in the open air, under 
the principal chimney of the New Museum at Berlin; ‘‘ during that 
time it was exposed to sunshine, mist, snow, and rain,” and never- 
theless ‘‘ retained its full brilliancy of colour.” 
The stereochrome has been adopted ona grand scale by Kaulbach 
in decorating the interior of the great national edifice at Berlin 
already alluded to. These decorations are now in progress, and 
will consist of historical pictures + (the dimensions of which are 
21 feet in height and 243 in width), single colossal figures, friezes, 
arabesques,.chiaro scuro, &c. On the effect of the three finished pic- 
tures, it has been remarked by one whose opinion is entitled to 
respect, that they have all the brilliancy and vigour of oil paintings, 
while there is the absence of that dazzling confusion which new oil 
paintings are apt to present, unless they are viewed in one direction, 
which the spectator has to seek for. 
Mr. A. Church has suggested that if the surface of oolitic stones 
(such as Caen-stone) is found to be protected by the process already 
described, it might be used, as a natural intonaco, to receive coloured 
designs, &c. for exterior decorations ; the painting would then be 
cemented to the stone by the action of the water-glass. 
Mr. Church has also executed designs of leaves on a sort of terra 
cotta, prepared from a variety of Way’s silica rock, consisting of 75 
parts clay and 25 of soluble silica. This surface, after being hardened 
by heat, is very well adapted for receiving colours in the first in- 
stance, and for retaining them after silication. 
(J. BJ 
* Communication from Mr. George Bunsen. 
+ Three of these pictures are finished : — 
1. The Fall of Babel. 
2. The Bliithe Griechenlands (‘the golden age of Grecian art and poetry’). 
3. The Fall of Jerusalem (an engraving of this picture was exhibited by Mr. 
Ackerman,)— Two other compositions are drawn, i. e. 
4. The Battle of the Huns. 
5. The Crusaders’ arrival before Jerusalem. 
6. The subject not yet decidedon. (Communication from Mr. G. Bunsen.) 
