THE GEOLOGIST. 
with organic matter, and continually send forth young vigorous 
shoots. To these may be added Triticum junceum, T. loliaceum, 
Hordeum maritimum, Poa maritima, P. bullosa, and Rotthollia in- 
curvata, the last a beautiful and rather rare grass, which becomes 
towards autumn of a deep yellow colour, gradually blending into 
a bright crimson ; besides these are certain species of Salsola, Beta, 
Galium, &c. among the dicotyledons which flourish upon the dunes or 
near the sea, especially where there is mud as well as sand. To them 
we must add two ligneous plants, which contribute more than any 
others to fix the movable sand of the dunes we speak of ; the one is 
a stunted willow, Salix cinerea (or a variety), with ash-coloured leaves ; 
the other, a remarkable plant, called the SeVbuckthorn (Hippophoia 
rhamnoides), is a thorny shrub, some four or five feet high, bearing a 
bright orange-coloured berry, like that of the holly. 
Some of these, and many other plants which we cannot mention 
hei-e,* might be cultivated with advantage on the sand-hills. Indeed, 
such has long been my conviction, aud in 1855 I intimated to the 
Belgian Government that the cultivation of maize or Indian corn, for its 
starch, in the more fertile parts of the dunes of Flanders, might meet 
with success. + Some years ago I called attention :[ also to this fact, 
that, if we consider a soil composed of pure clay, another of limestone 
or chalk, and a third of sand, it will be found that of these three, tlie 
one composed of pure sand is the most favourable to the development 
of vegetables. But the sand of the Flemish dunes is not quite 2)ure ; 
it is mixed up with a considerable quantity of debris of shells, the 
fragments of calcareous matter being reduced to the size of the grains 
of sand ; it reposes upon a sort of marl, — the well-known Argile (/rise 
d'Ostende, which in some places lies bare upon the sea-shore ; so that 
with a little trouble the movable sand-hills might be converted into 
a fixed and fertile soil, containing all the necessary elements, — sand, 
carbonate of lime, clay, organic matter, salts, &c. Add to this the 
purity of the maritime air, the presence of minute quantities of salt§ 
and iodide of sodium || in the sand, or, at least, this iodide is found in 
the plants of the dunes, though some say it has never been discovered 
in the sand on which they grow, and we shall not be so astonished at 
the remarkable fertility which some of the more favoured spots of these 
sand-hills present to us. 
* Amongst others a peculiar species of "Old Man" {Artemisia maritima), 
Sweet-briar, some species of Solanum, Viola, Lotus, Linum, Daucus, &c. 
+ See my Mcmoire sur la Fecule et les substances qui peuvent la remplacer dans 
V Industrie. Bruxclles, 1855-6, J. B. TLrcher. 
X Journal de la Societe des Sciences Medicates et Naturelles de Bmxelles. 
Oct. 1854. 
§ On the uses of salt in agiiciilture, see an excellent prize essay by my friend 
Dr. Max. De Saive, of Brussels, founder of the Veterinary School of Medicine 
at Liege, entitled "Mcmoire sur les usages du sel en Agriculture," and to which the 
Brussels Academy awarded their gold medal some years ago. — T. L. P. 
II A curious experiment was made some time since by M. Blengini, upon 
the effects of iodine and bromine on vegetation. Some seeds were found to 
germinate with astonishing rapidity if they were sprinkled over with a slight 
quantity of a solution of iodine, or iodide of sodium. — T. L. P. 
