FOREIGN CORRESPONDENX'E. 



33 



desired effect, the water of the streams augmeDted its intensity to such 

 a degree, that every one feared an explosion would have taken place. 



A little further on, we have a description of the Salines de rilerault, 

 or Salt-basins of Herault. They ase large quadrangular basins, in 

 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 fast 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 (7avarnie is fed by 

 the perpetual snows which cover the summit 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 just 

 appreciation of distances, that being placed one day near the falls, I 

 perceived 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 hrecJie de JRoland." — Here is 

 something similar in the chai rning Viev)s of Nature of Baron Von 

 Humboldt The transparency of mountain air is so gi'eat near the 

 equator, that, in the province of Quito, I was able to distinguish with- 

 out the aid of a telescope the white cloak (jjoncJio) 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 mountains of France, has produced many 

 different qualities of Kaolin, so extensively used in the manufacture 

 of porcelain. M. Lejeune infonns us that the white Kaolin of Saint- 

 Yrieux, near Limoges, notw^ithstandiug 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 

 ])orcelain-manufactory of Sevres since the year 17 Go, and not only 

 furnishes 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 

 forgotten to pick up a specimen of the common variety of Emerald 

 which serves to pave the coach-road from that town in the direction 

 of Paris. AVe 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 



