202 Flora of the Shores of the Firth of Forth. [Sess. 
ination, but no nearer than absolutely necessary. Do not 
take the plate out of the dish, and on no account hold it up 
to the light to look through it. The time required for correct 
development can be easily judged by practice, and by work- 
ing with a small clock in the dark room. The density can be 
deiely judged by turning the plate over and looking at the back 
when the time is nearly up. All white light must be care- 
fully excluded, even after the plate is put into the fixing bath. 
In photographing coloured pictures it is a good thing to 
have a strip of paper half black and half white, say at the 
foot of the subject. It will be found a great help in de- 
velopment to enable one to judge the correct density for the 
whites if there should happen to be none in the subject. Two 
photographs are shown in Plate XXIV. of Gilbey & Her- 
mann’s advertisement card for their coloured poster inks. 
The card was highly coloured. No. 1 is a photograph taken 
on an ordinary Paget xxx plate, and No. 2 one taken on a 
Cadett spectrum plate, through a yellow ray-filter. These two 
illustrations are a study in the photography of colour, and in 
many parts the one is the actual reverse of the other. 
[Many slides were exhibited of photographs of coloured 
subjects, such as flower-studies, &c., taken with ordinary 
plates, and also with orthochromatic plates, in order to show 
the advantage in using the latter.] 
X.—WNOTES ON THE FLORA OF THE SHORES 
OF THE FIRTH OF FORTH. 
By Mr MARK KING, Honorary MEMBER. 
(Read April 24, 1901.) 
TuE flora of Edinburgh and its vicinity has engaged a good 
deal of my attention during a number of years, although 
latterly I have confined my observations to the banks of 
the Forth from high-water mark to about a score of paces 
