133 
On the discolouration of white bricks made from cer- 
tain clays in the neighbourhood of Sydney. 
By Epwarp H. Rennie, M.A., D. Se. 
[Read before the Royal Society of N.S.W., 5 September, 1888.] 
(Preliminary communication.) 
Position for two years. On the side facing the south it was 
.. This led to a chemical investi ion of the yellow or green 
ue igation oO e yellow 
ae obtained by simply soaking the coloured portions of the 
. ater. It was found that this solution gave all the 
of vanadiec acid. 
