FOREIGN CORRESPONDENCE. 
85 
desired effect, the water of the streams augmented its intensity to such 
a degree, that every cue feared an explosion would have taken place. 
A little further on, we have a description of the ASalinefi de VlJcrmilt, 
or Salt-basins of Herault. They are large quadrangular basins, iu 
depth a few inches below the level of the sea, and surrounded by banks 
to retain the sea-water. The latter enters at high tide, by an opening 
which is then immediately closed, and a little fresh water is added 
from the neighbouring springs. By evaporation, the salt is deposited 
in thin crusts, and, as fivst as these form, new supplies of salt water are 
allowed to enter. When a layer of salt some 27 or 33 centimetres in 
thickness has been obtained, it is taken out and piled up into triangular 
heaps, which are covered with grass, rushes, &c. and allowed to dry, 
whilst awaiting exportation. 
The following is given by M. Lejeune concerning the falls of Ga- 
varnie : — " In the Hautes Pyrenees, the cascade of (iavarnie is fed by 
tiie perpetual snows which cover the siimmit of a circular wall of rock, 
having a vertical height of 389 metres. This circle is so vast, and the 
purity of the air in mountainous districts is so adverse to the ju.st 
appreciation of distances, that being placed one day near the falls, I 
jterceived something on the opposite side of the semicircle of rocky 
wall, that appeared to be a fly about to crawl over. . . . This fly turned 
out to be a smuggler on his way to the hrecJte de Eoland." — Here is 
something similar in the charming Views of Nature of Baron Von 
Humboldt : — " The transparency of mountain air is so great near the 
equator, that, in the province of Quito, I was able to distinguish with- 
out the aid of a telescope the white cloak (jxmcho) of a gentleman at a 
horizontal distance of 84,132 feet. ... It was my friend, M. Bonpland, 
who had just left the charming villa of the Marquis de Solvalegre, 
and was walking along the dark-coloured sides of the volcano of 
Pichincha." 
The decomposition of certain varieties of Granite, and above all of 
Pegmatite in the central m.ountains of France, has produced many 
different qualities of Kaolin, so extensively used in the manufacture 
of porcelain. M. Lejeune informs us that the white Kaolin of Saint- 
Yrieux, near Limoges, notwithstanding the great variety of rocks 
accumulated as it were in this district, is extremely pure. It is found 
to extend in a bed many kilometres long, and sometimes is seen 
penetrating the rocks, like lodes or veins, attaining here and there 
twenty metres in thickness. This bed of Kaolin has supplied the 
porcelain-manufactory of Sevres since the year 176.5, and not only 
famishes the best material to all the china-manufactories of Paris, but 
is even sent out to the United States of America. 
In passing near the town of Limoges, our author has evidently 
foi-gotten to pick up a specimen of the common variety of Emerald 
which serves to pave the coach-road from that town iu the direction 
of Paris. We will terminate here what we had to say of his book. 
It is written in a lively style, and is one which will contribute to 
inspire a taste for Geology, at the same time giving its readers a desire 
