196' 



ANALYSIS OF BRITISH AND FOREIGN SALT. 



purpose it is crushed to the proper size between iron rollers. 

 The trials which have been made, I am informed, are but 

 few, and the results hitherto are not perfectly known. 

 Bay salt, The bay salt imported from foreign countries is well known 



to be prepared by the spontaneous evaporation of seawater, 

 which, for this purpose, is confined in shallow pits, and ex- 

 posed to the full influence of the sun and air. I have no 

 addition to make to the accounts of its manufacture, which 

 have already been given by various writers*. 



Results of \$ the results of the investigation, which forms the sub- 



theexamina- . . t ,, . 



you ject of this memoir, may be acceptable to many persons, 



who can scarcely be expected to take an interest in a long 

 detail of analytical processes, I shall present in the follow- 

 ing section a general view of the experiments, and of the 

 and analyses, conclusions that may be deduced from them. In the last 

 place, in order that other chemists may be enabled to repeat 

 the analyses under similar circumstances, I shall describe 

 minutely the methods that were adopted, some of which are 

 new, and others reduced to greater precision. If however, 

 in the future progress of science, it should appear, that any 

 of these processes are imperfect, it may still be admitted, 

 that, for all useful purposes, they afford a, fair comparison of 

 . the composition of the several varieties of culinary salt ; 

 since the sources of fallacy, that may hereafter be disco- 

 • vered, must have been the same in every case, and have 



produced in each an errour of nearly the same amount. 



Sect. If. General Statement of the results of the Expert* 

 merits, and Conclusions that may he deduced from them, 



Different salts A comparison of the component parts of British and 

 foreign salts, and of different varieties of British salt with 

 each other, will best be made by an examination of the fol- 

 lowing table, which comprehends the results of the analysis 

 of equal weights of each variety. 



* Encvclnp. Methcx". Art. Salins. (Des Marais Salans). Aikin's Die 

 tionary of Chemistry, II, 224. Watson's Chemistry, Vol. II, p. 52. It 

 is necessary to remark, that a great proportion of what is sold in London 

 as bay salt is Cheshire large grained fishery salt. 



1000 



