* * * * * OBSERVATIONS ON THE BOILING POINT OF WATER. Water when exposed to a sufficient degree of heat, is gradually heated till it arrives at the 212th degree of Fahrenheit’s thermometer, after which it resolves itself into vapour, and becomes incapable of growing hotter; supposing, however, that the gravity of the atmosphere remaining the same; for upon high mountains it will boil, or assume the form of vapour in a lower degree of heat; hence in a mean heat of the barometer, the heat of boiling water has been always considered as a fixed and invariable point, namely, equal to the 212th degree of the thermometer; but Mr. Achard, willing to examine the truth of this position, or, in other words, willing to observe whether the heat of boiling water was subject to be altered by any other circumstance, besides the variable pressure of the atmosphere, made many experiments, the summary of which is, that the aperture of the vessel in which the water is boiled, occasions a variation, amounting to nearly one degree; the heat being greater when the aperture is narrower; and the substance of the vessel is also the cause of considerable variation; for if the vessel be made of glass, porcelain or other substance, which is a bad conductor of heat, the boiling point of water will be a constant degree, but if the vessel be of metal, all other circumstances being alike, then the heat of boiling water will be fluctuating. * * * * * * * * * _For the +New-York Weekly Magazine+._ * * * _TO TYRUNCULUS._