2T<f 



APPENDIX. 

 ** Sea- water contains chiefly a neutral fiilt, compofed of 

 " foffil alcali and marine acid. It likewife contains a fait 

 -*' which has magnefia for its bafis, and the fame acid. 

 " Thefe two falts are blended together in our common 

 " flit in England, which is prepared by quick boiling 

 *' down fea water. But when the procefs is carried on by 

 " the fun, or a flow heat, they may be colleded fepa- 

 " rately ; that which has the foflil alcali for its bafis 

 *' cryftallizing firfl: ; and this is of a vafUy fuperior quality 

 ** for prcferving meat, and for the other culinary pur- 

 " pofcs. The mother liquor now remaining, being 

 '* evaporated, affords a vitriolic magnefia fait, which in 

 " England is manufaftured in large quantities, under the 

 " name of E.pfom fait. 



" Befides thefe falts, which are objecls of trade, fea- 

 " water contains a felenitlc fait, a little true Glauber's fait, 

 " often a little nitre, and always a quantity of gypfeous 

 " earth fufpended by means of fixed air. 



*' The fpecific gravity of fea-water to that of pure dif- 

 " tilled water, is at the Nore as looo to 1024,6; in the 

 *' North fea as 1000 to 1028,02. 



*' The quantity of fait obtained by boiling fea-water in 

 *' different latitudes, from 51° 30' to 8o°,43 N. L. is in- 

 *' ferted in a table in the former part of this Appendix. 



*' Sea- water, 



