226 Miscellaneous Intelligence. 
various buildings, and of which he intends to publish specimens. 
He has selected the above beautiful structure as the first publi- 
cation, because, in addition to its intrinsic value as a work of 
art, it appears particularly interesting at this time, in conse- 
quence of the proposed rebuilding of London Bridge. 
Il. CHEMICAL SCIENCE. 
1. Tincture of Brazil Wood, asa re-agent. By Mr. P. A. de 
Bonsdorff.—It is known that the colouring matter of the Brazil 
wood, treated with an alkaline solution, affords a very fine violet 
colour. But it possesses another property of some interest to 
chemistry, that of distinguishing one acid from another, in 
certain cases. Sulphuric acid, concentrated, or diluted with 
3 parts of water, instantly gives to paper stained with Brazil 
wood, a bright rose-colour, which, gradually attracting humi- 
dity from the air, passes to orange. Diluted with a little more 
water, the acid produces a colour bordering on yellow; and 
with 20 or 30 parts of water it gives, at the end of a minute, 
a yellow or yellowish colour, which grows dulland dirty. Nitric 
and muriatic acids have the same habitudes with this colour as 
the sulphuric. Gaseous sulphurous acid completely blanches 
moistened Brazil-wood paper. Concentrated hydriodic acid 
yields a rose-colour, which becomes by degrees yellow on the 
edges, and, after some days, altogether yellow. Diluted with 
water, it gives, after half a minute, a tolerably fine yellow, 
which, however, soon begins to fade. After some hours it is 
fainter, and more red than yellow. Jodic acid gives immediately 
a pale and dull yellow, which remains unchanged. Fluoric 
acid, whether pure, or combined with silica, causes a clear red 
colour. Diluted, it re-acts in a very decided manner; it in- 
stantly produces a fine lemon-yellow colour, which, in the space 
of a minute, disappears, and soon leaves a tint of greenish-gray, 
which, observed by transmission, is of an olive-green. In cases 
where the fluoric acid is evolved in a gaseous form, it is suffi- 
cient to submit to its action for a few seconds moistened Brazil- 
wood paper. The paper passes through the above transitions 
of colour, a phenomenon which does not occur with any of the 
other volatile acids. Fuoboric acid has the same habitudes as 
the fluoric. Boracic acid does not act at first, but by-and- 
by the colour of the paper becomes pale, and ends in a white, 
bordering very little on red. If boracic acid contain traces of 
sulphuric acid, (which always happens when it is not purified by 
repeated crystallizations,) its re-action gives rise immediately 
to a very marked yellowish colour, which soon disappears. The 
native boracic acid of the island of Volcano, presents very evi- 
