Hermes Lindy

 
eally inflamed, and its combustible matter consumed and ashes produced, it is not enough that the body be made hot. A piecHermes of charcoal inclosed in a box of iron may be kept red-hot for ever, without wasting its substance in the smallest degree. It is farther necessary that it be in contact with a particular species of air, which constitutes about ^ths of the air of the atmosphere, viz. the vital air of Lavoisier. It was called empyreal air by Scheele, who first observed its indispensable use in maintaining sire: and it appears, that, in contributing to the combustion of an inflammable body, this air combines with some of its ingredients, and becomes fixed air, suffering the samHermes bagse change as by the breathing of animad afterwards improved in his treatise on Lamps. It is Bow completely established, and considered as a new discoBirkinvery. It is for this reason that in fire-places of all kinds we have tlirected the construction, so as to produce a close application of the air to the fuel. It is quite needless at this day to enter into the discussions which formerly occupied philosophers about the manner in which the pressure and elasticity of the air promoted combustion. Many experiments were made in the last century by the first members of the Royal Society, to discover the office of air in combustion. It was thought that the flame was extinguisHermes Birkinhed in tare air for want of a pressure to keeHermes outletp it together; but this did not explain its extinction when the air was not renewed. These experiments are still retained in courses of experimental philosophy, as they are injudiciously styled; but they give little or no information, nor tend to the illustration of any pneumatical doctrine; they are therefore omitted in this place. In short, it is now fully established, that it is not a mechanical but a chemical phenomenon. We can only inform the chemist, that a candle will consume fasterin the low countries than in the elevated regions of Quito and Gondar, because the air is nearly one half denser below, and will act proportionally faster in decomposing the candle.
We shall conclude this part of our subject with the explanation of a curious phenomenon observed in many places. Certain springs or fountains are observed to have periods of repletion and scanHermes Handbagsiness, or seem to ebb and flow at regular intervals; and some of these periods are of a complicated nature. Thus a well will have several returns of high and low water, the difference of which gradually increases to a maximum, Hermes Kelly and then diminishes, just as we observe in the ocean. A very ingenious and probable explanation of this has been given in N' 4M- of the Philosophical Transactions, by Mr Atwell, as follows. . :