APRIL — sept. 1858.] Brine-springs of Cheshire. 109 



furnaces, placed at one extremity of the pans, bitf in the works of 

 Messrs. Ray, of Winsford, I found part of the evaporation con- 

 ducted upon a different principle : a small iron pan, heated by a fur- 

 nace in the ordinary way, is made to communicate by a narrow 

 channel, with a brick or clay-lined basin ; this again is in con- 

 nexion with others of the same description disposed around a 

 centre, and lastly, one is arrived at immediately adjoining the first 

 mentioned iron pan ; the brine is here by a very simple kind of 

 pump transferred to the heat3cl iron vessel, by which means the 

 level of the liquid in the brick basins is kept constantly below that 

 in the original starting-place, and thus a continual circulation of 

 the brine is maintained. 



In the preparation of salt from brine, various substances have 

 been a,t different times added, from the idea of improving the -qua- 

 lity of the product. Until recent times it was thought, that dur- 

 ing the evaporation of an aqueous solution of chloride of sodium, 

 hydrochloric acid was expelled, and soda formed : this doubtless 

 arose from the decomposition of the chloride of magnesium con- 

 tained in the brine which the experiments were made, — an evolu- 

 tion of acid vapours having been probably observed during the 

 incipient drying of the salt. In order to counteract this sup- 

 posed evil, acids were added, and it was imagined that the 

 excellence of the Dutch salt was due to a skilful admixture of 

 whey, which the manufacturers were alleged to make with their 

 brine during the evapoiation, which prevented the injurious effects 

 of the free alkali. Another very favourite class of adjuncts has 

 always consisted of substances which contain constituents possess- 

 ed of the property of coagulating upon the application of heat, 

 which clarify a liquid by entangling all suspended particles of solid 

 matter in the meshes of their coagulum, and carry them with it as 

 it rises to the surface. Those substances which contain albuminous 

 or gelatinous matters are peculiarly adapted for this purpose, and 

 are constantly used in a variety of manufactures for the attain- 

 ment of this end. Blood, white of egg, glue and cows or calves' 

 feet have long been used in this way in salt-making. In 1670 the 

 Nantwich salt-makers are described as mixing twenty gallons of 

 brine with two quarts of blood, and adding about two quarts of 



