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cantat carmina cordi pessimo. Acetum quippe si mitlalurin liitrum, protinus ehullit.”
As the above extract from St. Jerome is often referred to,it is inserted here in the original, to afford the public anopportunity to form their own opinion.
We should not omit to mention, that Herodotus , in thatpassage where he describes the method the Egyptians ob-served in embalming dead bodies, also mentions nitrum asan ingredient used. Some Greeks, it is said, pronouncethis word lilron.
Men, in the course of time, are said to have becomeacquainted with the purer and more useful, at the sametime, more easily to be acquired, mineral alkali, which wasfurnished under the name of soda, by the Moors and inha-bitants of southern Africa, who had learnt the method ofpreparing it. The vegetable alkali was also frequently ma-nufactured in their woody districts, and became an articlein great request, and was sold under the name of potash,cineres clavellal.
From those improvements all knowledge of the impurealkali from the incrustation of walls fell into disuse; andthere being no further occasion to guard against the confu-sion resulting from names, it was thought no longer neces-sary to name saltpetre sal nitre, it was called nitrum ,- theoldest signification of this w r ord by degrees being forgotten,it was admitted, without further examination, that thenitrum of antiquity was nothing more than our saltpetre.
Those learned and scientific travellers, Peter Belloni andProsper Alpinus , travelling through the east in the vicinityof Byzantium, in the fifteenth century, heard the article ofmineral alkali, hitherto called nitrum, denominated by theinhabitants of that district NATRUM, they introduced thislatter name into their works, whence the change of nomemclature took place.
Linnaeus , in 1736, also adopted the same term in hisclassification of mineral alkalies; in this he was followed byWallerius, w'ho also includes the oriental mineral. Afterthese illustrious examples, the word natrum has been gene-rally adopted by subsequent geological writers.
It affords us pleasure to remark, that in the early part ofthe last century, our own ingenious countryman, the Hon.Mr. Boyle, had examined and determined the differencebetween the fixed and volatile alkalies: however geologistsand chymists, till the latest periods, believed all fixed alkaliwas produced by the incineration of vegetables; to deter-mine this and fix it upon the public mind, however, we are