( 3^5 )

nic heat, as fliewn in Essay I. therefore itcould not have obtained as early a possessionof the above-mentioned bases as the marine.This point is important, and may be provedin another manner : If the vitriolic andmarine acids were coetaneous, they musthave obtained a simultaneous possession ofthe bases to which they both have thestrongest affinity, viz. natron and calcare-ous earth* and, as aster pofieffing the na-tron, there was still a sufficiency of calca-reous earth to saturate the residue of bothof them, there should neither at first nor atpresent be any such thing in the sea as mu-riated magnesia, of which, however, it con-tains, as we have seen, nearly i per cent.but the sea would at first contain Glauber,common salt, and muriated and variolatedlime, and soon after (as Glauber’s salt andmuriated lime decompose each other,) itwould contain common salt and gypsum,and at last, as gypsum is decomposed byaerated magnesia, we should have in the seaat this day, common salt and Epsom saltonly, or at most only common salt, Epfomand selenite, it being possible that theremight not be enough of magnesia to de-compose