93 
of British and Foreign Salt. 
therefore, is produced in the brine, and the slowness of the 
process, which lasts from 7 or 8 to 10 days, allows the mu- 
riate of soda to form in large, and nearly cubical crystals, 
seldom however quite perfect in their shape.* 
For ordinary domestic uses, stoved salt is perfectly sufficient. 
Common salt is adapted to the striking and salting of pro- 
visions, which are not intended for sea voyages or warm 
climates. For the latter purposes, the large grained or fishery 
salt is peculiarly fitted. 
On the eastern and western coasts of Scotland, and espe- 
cially on the shores of the Firth of Forth, large quantities of 
salt are made by the evaporation of sea water. In consequence 
of the cheapness of fuel, the process is carried on, from first 
to last, by artificial heat, at a temperature, I believe, equal or 
nearly so to the boiling point, and varying, therefore, accord- 
ing to the concentration of the brine. The kind of salt, chiefly 
formed in Scotland, approaches most nearly to the character 
of stoved salt. In some places a salt is prepared, termed 
Sunday salt ; so called, in consequence of the fires being 
slackened between Saturday and Monday, which increases 
considerably the size of the crystals. 
I am indebted to Dr. Thomson of Edinburgh, (who gave 
me his assistance with great zeal and alacrity ) for an oppor- 
tunity of examining upwards of twenty specimens of Scotch 
salt, prepared by different manufacturers. That distinguished 
chemist, it appears from a letter which he addressed to me on 
the subject, was some time ago engaged in experiments on 
Cheshire salt. The particulars he has lost ; and he retains 
only a general recollection of the facts, which confirms, I am 
* Cheshire Reports, p 53, &c. 
