12 On Changing the Colour of the Hydrangea Hortensis. 
were the trusses of flowers any thing near so large as wlien free from 
it, and the colour was by no means a good blue. I next had re- 
course to a kind of peat-earth which appeared to contain a small portion 
of the oxide of iron ; the plants in this grew very healthy, and bore 
large trusses of flowers — but these too were far from being of a good 
blue. Nevertheless, I am satisfied that when the soil can be obtained 
with a good portion of the oxide of iron, the flowers will be blue ; but 
as I found this to be a method on which a practical gardener could by 
no means permanently depend, I was very anxious to discover some- 
thing that would answer the desired end. All the means I made use of 
proved ineff'ectual, and I was forced, though reluctantly, to give up the 
experiment ; but coming into the neighbourhood in which I now reside, 
I was much struck with the vigorous and healthy slate of the Hydran- 
geas kept by the cottagers here : the flowers are of an exquisitely fine 
blue, and in size the trusses are surpassed by none I ever saw, and a 
particular friend of mine who had lived some years in the neighbour- 
hood, assured me, that every year they blow the same beautiful colour. 
The compost they are potted in, is common sandy loam, mixed with 
about one third of fresh sheep'' s dung. A portion of the same dung is 
mixed with the water that is given to the plant, and I am informed that 
the young plants, which have been grown in all parts of the village, 
that have received this treatment, the same effects have been produced. 
As I have not hitherto, had an opportunity of proving the experiments 
myself, I beg leave to submit it to the notice of your readers, some of 
whom, may porliaps have used similar means. 
I ain, Gentlemen, 
Yours' &c. 
May -lAth, 1831. Ri'sricus. 
Article IV. — Arboriculture. — On llie Neylcct of Forest 
Planting, in Great-Britain. By QuERCUS 
Gextlemex, 
I HAVE received yom* circular, inclosing a prospectus of your 
contemplated Horticultiu-al Register, and to prove to you that J am 
sincere in my wishes ibr the success of your undertaking, J sliall 
endeavour to comply with the request A\ith \\hich the prospectus con- 
cludes. In doing so, 1 shall attempt to dii-ect the attention of gardeners, 
and others, to the science of AKBORrcuLTURE, a branch of rural eco- 
nomy, which, in addition to their multifarious duties, gardeners are 
frequently required to superintend : but to which, neither they, nor 
persons, who as foresters imdertake the management of wooded lands, 
