On Changing ilie Colour of the Hydrmigea, SfC. 497 
Article X. — On Changing the Colour of the Flowers of 
the Hydrangea Hortensis^ — Treatment of the Disdndra 
Prostrata^ — and on Preserving Sea-Weeds. By M. G., 
near Croweii, Norfolk. 
I PARTICULARLY observed the remarks at page 11, "On changing the 
Colour of the Flowers of the HT/f/rtingea /ior<^?i*7S." ! have tried the 
experiment in another way to the one there mentioned, with perfect suc- 
cess, I placed a young plant in a pot, and kept it in the house in a 
west window, regularly watering it with rain water, in which alum was 
dissolved. Small lumps of alum were constantly kept in the water, 
which was allowed to absorb as much as it would. I did not weigh the 
alum, but I calculate it was about 1 lb in the year, this was used to 
water one plant. This plant produced one bunch of flowers only, but 
they were of a very pleasant and true blue; and the same plant is still 
treated in this manner, so that I hope this year also to have some good 
blue flowers. I do not think it grows so vigorously as the parent plant, 
which has been growing on a warm south bank, in the open ground, for 
the last ten years, without any covering in the winters. It has acquired 
the height and size of a large currant bush, and has at the same time 
produced as many as 35 bunches of superb blossoms. 
I have for some time also cultivated a plant of the Trailing Disandra, 
[Disdndra prostrdta,) which grew so weak that two years ago, I cut it 
down rather short, and placed it on a bracket opposite a west window, 
in a small room. It has now attained the length of 9 feet, and is a full 
and handsome plant ; 3 feet in length rest on the floor of the room. It 
is constantly watered with water in which toasted bread has been steeped, 
and I wish to ask you whether you think its luxuriance in any degree 
arises from that circumstance .'' * 
Your mentioning in page 142, a method of drying and preparing Sea- 
weeds for an herbarium, leads me to name another system, which any 
of your readers unacquainted with it, may be glad to learn. I made for 
this purpose a tray of well-seasoned oak, full half an inch thick, 1 3 
inches square, and two inches and a half deep. At the bottom, in one 
corner, is fixed a very small brass cock. The tray is filled with water, 
and a paper is placed in it ; the Sea-weed is then spread with a bodkin 
or fine wooden point on the paper. The cock is then turned, and the 
water allowed to drain off" slowly. The Sea-weed remains on the paper 
better displayed than by any other means that I have been able to learn. 
It may then be dried between a few leaves of blotting paper, with a 
sentle pressure. 
^ M. G. 
February 16, 1832. 
* We conceive ll>e toast-water can be of no advantaire, except tliat Uie water is rendered 
much of tlie same temperature as the room in wliich the plant is s'^^ing, which is always 
exceedingly beneficial to the health and vigour of all plants. — CoNU. 
Vol. I, No. 11. 3 Q 
