HYDROMETERS.
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known to Amoldus de Villa Nova. But does not say, itwas an Hungarian invention; being silent upon that cir-cumstance.
HYDROMETERS.
The Hydrometer is an instrument for admeasuring liquids ;its Greek name is utyotrxoTnov, hydroscopium, also called hy-
f roscopium, hyyrobaroscopium, areometrum, and baryllion.
t is an instrument by which the strength or specificgravity of different fluids is discovered, by the depth towhich it sinks in them. It has been chiefly used for dis-covering the contents of different salt water, withoutanalysis: and is now chiefly used by those whose concernsare in the spirit trade, to discover the different degrees ofstrength, and wdiat alloy they will bear; hence its utility tothe manufacturer and to the excise officer, is apparent.
The laws respecting the comparative weight of differentfluids, as well as of solid bodies immersed in them, was,we may recollect, first discovered by that great geometricianArchimedes, (the occasion being before recounted in a pre-vious article, it shall not be here repeated.) It may befar from improbable that Archimedes constructed this in-strument himself; in case he did, it must have been inventedsome few years before his death, which happened 212 yearsbefore the Christian era.
The most ancient mention of this instrument, by itsspecific name, occurs in the fifth century of our era, uponthe following occasion. The anecdote is very singular andaffecting, and also evinces the incapacity of humanity toact consistent and as it ought, when we suffer ourselves tobe directed by passions unworthy of the human character.
It is first discovered in those letters of Synesivs to thephilosophic and beautiful Hypatia; we trust we may beexcused the liberty we propose to take in detailing thiscircumstance, it not being generally known; and as its
partem decimam, et sicut cum aliis fieri solet vinb, scutella perforata tegatur, uteffervescat et rorismarini virtutes extrahat. Si vero lubet, postquam aliquidmusti et rorismarini in cucurbita vitrea, cujus beneficio alias quinta essentia estdistillanda, simul ebullient, quintam essentiam inde elicere ; id fieri poterit; etpostquam distillata fuerit, in vas mustum alterum cum roremarino, jam coutinens,post hujus fermentationem, est infundenda. Addita enim tam modica quintsessentiae hac quantitate, mustum eo fragrantius et etficacins reddetur. Joh. Bapt .Zapata, Medici Romani, Mirabiliu seu secreta Medico-Chirwgica - - per Davider*Splcittium. Ulmiie, 1696.