[ 86 j 



XVI. On the Mode of' mantifacturing Salt by Evaporation on 

 Faggots. By R. Bakewell, Esq.* 



T I "'HE salt-works at Montiers in the Tarentaise are particu- 

 ■■■ larly deserving attention, being perhaps the best con- 

 ducted of any in Europe with respect to economy. Nearly 

 three million pounds of salts f are extracted annually from a 

 source of water which would scarcely be noticed, except for 

 medical purposes, in any other country. 



The springs that supply the salt-works at Montiers rise at 

 the bottom of a nearly perpendicular rock of limestone, on 

 the south side of a deep valley or gorge through which the 

 Doron runs before it joins the Isere. The distance of the 

 salt-works from the spring is about a mile ; the water runs 

 in an open canal, but is received in a reservoir, where it de- 

 posits part of its ochreous contents. The water rises from 

 the rock with considerable force, and emits much gas, which 

 is principally carbonic with a mixtiu - e of sulphuretted hydro- 

 gen ; it has an acidulous and slightly saline taste. The tem- 

 perature of the strongest spring is 99° Fahrenheit ; it contains 

 1*83 per cent, of saline matter. The second spring has the 

 temperature of 95°, and contains 1 '75 of saline matter. Be- 

 sides common salt, the water contains in small proportions 

 sulphate of lime, sulphate of soda, and sulphate and muriate of 

 magnesia; together with oxide of iron. During the great 

 earthquake that destroyed Lisbon in 1756, the salines at 

 Montiers ceased to flow for forty-eight hours ; and when they 

 flowed again, their quantity was increased, but the saline im- 

 pregnation was weaker J. It may seem extraordinary that 

 the waters at Montiers, which have only half the strength of 

 sea water, should repay the expense of evaporation ; but the 

 process by which it is effected is both simple and ingenious, 

 and might be introduced with great advantage on many parts 

 of our own coast, should the salt duty be entirely removed. 

 The salt-works at Bex in the Pays de Vaud are nearly similar 

 to those at Montiers, but not on so extensive a scale, and a 

 very useful part of the process at Montiers is not adopted at 

 Bex. 



* Extracted from volume i. of" Travels in the Tarentaise, and various 

 Parts of the Grecian and Pennine Alps, and in Switzerland and Auvergne, 

 in the Years 1820, 1821, and 1822." In 2 vols, octavo. 



•j- In this quantity are comprised common salt, Glauber's salt, and the 

 alkaline salts sold to the glass manufacturers. 



% The geological position of these springs, and the numerous thermal 

 waters of the central chasm of the Alps, are described in the latter part of 

 the volume. 



I shall 



