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XVTTT. An Analysis of several Varieties of British and 

 Foreign Salt, (Muriate of Soda,) with a view to ex- 

 plain their Fitness for different ceconomical Purposes, Bif 

 William Henry, M.D. F.R.S. Vice-Pres. of the Li- 

 terary and Philosophical Society, arid Physician to the 

 Infirmary at Manchester*. 



Sect. I. General Observations. 



JLn undertaking the series of experiments described in the 

 following pages, I had not so much in view the discovery 

 of novelties in science, as the determination, by the careful 

 employment of known processes, and by the improvement 

 of methods of analysis, of a number of facts, the establish- 

 ment of which (it appeared to me probable) might have an 

 influence on an important branch of national revenue and 

 industry. 



An opinion has for some time past existed, and I believe 

 has been pretty general both in this and other countries, to 

 the disadvantage of British salt as a preserver of animal 

 food; and a decided preference has been given to the salt 

 procured from France, Spain, Portugal, and other warm 

 climates, where it is prepared by the spontaneous evapora- 

 tion of sea water. In conformity with this opinion, large 

 sums of money are annually paid to foreign nations, for 

 the supply of an article, which Great Britain possesses, be- 

 yond almost any other country in Europe, the means of 

 drawing from her own internal resources. It becomes, 

 therefore, of much consequence to ascertain, whether this 

 preference of foreign salt be founded on accurate ex- 

 perience, or be merely a matter of prejudice; and, in the 



Grains. 

 White lyas, with shining spangles, of Wells . . . . 1| 



Brown kmestone, of Plymouth .. .. .. i 



of Chidley (Chidgley ?) . . . . 0| 



Forty grains of burnt lime in flower, dissolved in aquafortis, left of clayey 

 ipatter when dried in the sun, as follows, viz. 



Blue lyas, of Watchet . . . . . . . . 4{ 



-• — of Briddistow . . . . . . . . Jtt 



The Watchet (residuum) made into a ball just stuck together, the Brid- 

 distow scarcely." 



When I wasai the house of Mr. Jessop the engineer (who was formerly a 

 pupil and ass'srant of Mr. Smcatoi:) at Butterley in Derbyshire, he mentioned 

 that a Mr. 'JofteU, a civil engineer of the southern part of Yorkshire, formed 

 a design 30 years ago, of investigating the British strata. I shall he thank- 

 ful to any of your readers who can communicate any particulars of this 

 undertaking, and of its author, if they will do so. 



* From Philosophical Transactions for 18 1Q, Fart I. 



former 



