Puslapio vaizdai
PDF
„ePub“

ture were capable of enjoyment, the wifeft might lament that ignorance which adınitted fo little fatisfaction. But Providence has diftributed to all, that all might render their tribute of gratitude; no one can plead ignorance of this, no ftation of life is exempt from this. While we readily own that whoever has attained fuperior knowledge, whether of the caufes of things or their combinations, whether of their diverfified utility, or their many-operative powers, fuch an one has much to inform his mind, to entertain his reflection, to amufe his imagination, to invigorate his understanding. Such an one may congratulate himself on the advantages of his ftation, and while without reluctance he admits all as common fharers in general benefits, let him highly value thofe attainments which contribute to his individual fatisfaction and felicity.

LEC

[ocr errors][merged small][merged small]

LECTURE XI.

LADIES AND Gentlemen,

A

FTER air we place water; a fluid, whofe abundance and universality, has exposed it to the strictest trials and experiments of the most accurate philofophers; who yet have little to boast in refpect of knowing its nature or compofition, beyond the veriest ruftic who without enquiry flakes his thirst in the ftream. What we know of it, refolves into a confeffion of its powers, its usefulness, and its general distribution throughout every part of nature. It is true, this latter idea (its. general diftribution) efcapes the obfervation of our fenfes, and eludes the remarks of curiofity itself, which startles at the fuggeftion, that the most folid bodies we know are very greatly compofitions of water !---and yet this is fact. Water is (next perhaps to fire) the most fluid body in nature, it penetrates where air is unable, and oozes---not through chinks, but through pores too fmall for the paffage of any other fluid. A variety of experiments places this beyond a doubt and a veffel impervious to water, is under no apprehenfion of trans mitting other liquors. We own, indeed, that water is not always fo fudden in burfting from confinement as air, which rushes out vehemently at once, if opportunity be offered; or as

quickfilver, which, because of its weight, takes inftant advantage of the fmalleft crevice; but though lefs hafty, it is more certain, and in the end accomplishes its purpose where those fluids fail. Air will not pass through leather, but water will; a fact useful to the negroes of Africa, who cool their water by hanging leathern bottles of it in the open air, the water pervades the pores of thefe bags, and by its evaporation cooling them and their contents, affords a pleasanter and more refrigerating beverage to the parched inhabitants of the torrid zone. Water will also escape through a bladder, where air will not; and the famous Florentine experiment informs us, that even the pores of gold are not fufficiently fine to refufe this element paffage.---To examine this, a hollow ball of gold was filled with water, and firmly closed, then preffed with great force by huge fcrews, till the imprisoned element permeated its confinement, and stood upon the furface of the globe in the form of

dew.

If water be thus capable of paffing bodies the most solid, and by the fineness and smallness of its parts, of pervading their receffes, it becomes evident there is no impoffibility attending the fuppofition, that it may also form a part of their compofition. This is demonftrable with little labour; for whether we submit to the operation of the chemical furnace, vegetables, in which this principle abounds, or parts of animals, (such as bones,) or foffils, all yield water: and this ingredient is often separated from its fubject by a gentle heat. By a little further advance, the hardest ftones, metals, falts, and fulphurs, yield water plentifully. It is true, the fire feems unable to treat all

fubjects

« AnkstesnisTęsti »