inaEUvityof Matter, & c * yr

theses explain elasticity by elasticity Whencethe particles of air must repel, and keep eachother at a distance: and the repulsive force vmust be conceived to be between every par-ticle alike. For is it were not, the greaterforce would still prevail on the less, disposingthe particles at equal distances, till an equi-librium were settled through the whole mass.Therefore any quantity of air, how little so-ever, repels all the rest as strongly, as it isrepelled by it: or the force of any part coun~teraSls the force of the whole mass. Thisforce is equal to the weight of the whole su-perincumbent atmosphere; or the weight ofa column of water thirty one feet high, or

ton speaking of this, (Opt, p. 371. edit. 3. J fays, “ It“ seems also to follow from the production of air and“ vapour. The particles, when they are shaken off“ from bodies by heat or fermentation, so soon as they** are beyond the reach of the attraction of the body,

“ receding from it, and also from one another, withtc great strength, and keeping at a distance, so as some-“ times to take up above a million of times more space* c than they did before in the form of a dense body.Which vast contraction and expansion seems unintel-“ ligible, by feigning the particles of air to be springy" and ramous, or rolled up like hoops, or by any othermeans than a repulsive power,”

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