ine: at the same time, I
must confess that my guide did not suffer at all, and was
astonished that one day's deprivation should be so troublesome to
me.

I have several times alluded to the surface of the ground being
incrusted with salt. This phenomenon is quite different from that
of the salinas, and more extraordinary. In many parts of South
America, wherever the climate is moderately dry, these
incrustations occur; but I have nowhere seen them so abundant as
near Bahia Blanca. The salt here, and in other parts of Patagonia,
consists chiefly of sulphate of soda with some common salt. As long
as the ground remains moist in the salitrales (as the Spaniards
improperly call them, mistaking this substance for saltpetre),
nothing is to be seen but an extensive plain composed of a black,
muddy soil, supporting scattered tufts of succulent plants. On
returning through one of these tracts, after a week's hot weather,
one is surprised to see square miles of the plain white, as if from
a slight fall of snow, here and there heaped up by the wind into
little drifts. This latter appearance is chiefly caused by the
salts being drawn up, during the slow evaporation of the moisture,
round blades of dead grass, stumps of wood, and pieces of broken
earth, instead of being crystallised at the bottoms of the puddles
of water.

The salitrales occur either on level tracts elevated only a few
feet above the level of the sea, or on alluvial land bordering
rivers. M. Parchappe found that the saline incrustation on the
plain, at the distance of some miles from the sea, consisted
chiefly of sulphate of soda, with only seven per cent of common
salt; whilst nearer to the coast, the common salt increased to 37
parts in a hundred. (4/7. "Voyage dans l'Amerique Merid." par M. A.
d'Orbigny. Part. Hist. tome 1 page 664.) This circumstance would
tempt one to believe that the sulphate of soda is generated in the
soil, from the muriate left on the surface during the slow and
recent elevation of this dry country. The whole phenomenon is well
worthy the attention of naturalists. Have the succulent,
salt-loving plants, which are well known to contain much soda, the
power of decomposing the muriate? Does the black fetid mud,
abounding with organic matter, yield the sulphur and ultimately the
sulphuric acid?

Two days afterwards I again rode to the harbour: when not far from
our destination, my companion, the same man as before, spied three
people hunt