their activity from the fulphurs joined with them. From which also, as hath been faid, he derives all their kinds and differences (g). Salt, water, oil, and earth feem to be originally the fame in all vegetables. All the difference, according to the chemifts, arifeth from a fpirit refiding in the oil, called the Rector or Archæus. This is otherwise called by chemifts, ens primum, or the native fpirit, whereon depend, and wherein are contained, the peculiar flavour and odour, the specific qualities and virtues of the plant.

137. These native spirits or vegetable fouls are all breathed or exhaled into the air, which seems the receptacle as well as fource of all fublunary forms, the great mass or chaos which imparts and` receives them. The air, or atmosphere, that furrounds our earth, contains a mixture of all the active volatile parts of the whole habitable world, that is, of all vegetables, minerals, and animals. Whatever perfpires, corrupts, or exhales, impregnates the air; which, being acted upon by the folar fire, produceth within itself all forts of chemical operations, difpenfing again thofe falts and spirits in new generations, which it had received from putrefac

tions.

138. The perpetual ofcillations of this elaftic and restless element operate without ceafing, on all things that have life, whether animal or vegetable, keeping their fibres, veffels, and fluids in a motion always changing; as heat, cold, moisture, dryness, and other causes alter the elasticity of the air. Which accounts, it must be owned, for many effects. But there are many more which must be derived from other principles or qualities in the air. Thus iron and copper are corroded and gather ruft in the air, and bodies of all forts are diffolved or corrupted, (g) 129.

which theweth an acid to abound and diffuse itself throughout the air.

139. By this fame air fire is kindled, the lamp of life preserved, respiration, digeftion, nutrition, the pulfe of the heart and motion of all the muscles seem to be performed. Air therefore is a general agent, not only exerting its own, but calling forth the qualities or powers of all other bodies, by a divifion, comminution, and agitation of their particles, caufing them to fly off and become volatile and active.

140. Nothing ferments, vegetates, or putrefies without air, which operates with all the virtues of the bodies included in it; that is, of all nature; there being no drug, falutary or poisonous, whose virtues are not breathed into the air. The air therefore is an active mafs of numberlefs different principles, the general fource of corruption and generation; on one hand dividing, abrading, and carrying off the particles of bodies, that is, corrupting or diffolving them; on the other, producing new ones into being; deftroying and bestowing forms without intermiffion.

141. The feeds of things feem to lye latent in the air, ready to appear and produce their kind, whenever they light on a proper matrix. The extremely small feeds of fern, moffes, mushrooms, and fome other plants are concealed and wafted about in the air, every part whereof feems replete with feeds of one kind or other. The whole atmosphere seems alive. There is every where acid to corrode, and feed to engender. Iron will ruft, and mold will grow in all places. Virgin earth becomes fertile, crops of new plants ever and anon fhew themselves; all which demonftrates the air to be a common feminary and receptable of all vivify ing principles.

142. Air may alfo be faid to be the feminary of minerals and metals, as it is of vegetables. Mr. Boyle informs us, that the exhaufted ores of tin and iron being expofed to the air become again impregnated with metal, and that ore of alum having left it's falt recovers it after the fame manner. And numberless inftances there are of falts produced by the air, that vaft collection or treasury of active principles, from which all fublunary bodies feem to derive their forms, and on which animals depend for their life and breath.

143. That there is fome latent vivifying spirit difperfed throughout the air common experience theweth; inafmuch as it is neceffary both to vege tables and animals (b) whether terreftrial or aquatic, neither beafts, infects, birds, nor fifhes being able to fubfift without air. Nor doth all air fuffice, there being fome quality or ingredient, of which when air is deprived, it becometh unfit to maintain either life or flame. And this even though the air should retain it's elafticity; which, by the bye, is an argument that air doth not act only as an antagonilt to the intercoftal mufcles. It hath both that and many other ufes. . It gives and preferves a proper tone to the veffels: this elaftic fluid pro motes all fecretions: it's ofcillations keep every part in motion: it pervades and actuates the whole animal fyftem, producing great variety of effects, and even oppofite in different parts, cooling at the fame time and heating, diftending and contracting, coagulating and refolving, giving and taking, fuf taining life and impairing it, prefling without and expanding within, abrading fome parts, at the fame time infinuating and fupplying others, producing various vibrations in the fibres, and fer

(5) 138, 139.

ments

ments in the fluids; all which muft needs enfure from fuch a fubtile, active, heterogeneous and elaftic fluid.

144. But there is, as we have obferved, fome one quality or ingredient in the air, on which life more immediately and principally depends. What that is, though men are not agreed, yet it is agreed it must be the fame thing that fupports the vital and the common flame; it being found that when air, by often breathing in it, is become unfit for the one, it will no longer ferve for the other. The like is obfervable in poifonous damps or fteams, wherein flame cannot be kindled. As is evident in the Grotto del cane near Naples. And here it occurs, to recommend the plunging them into cold water, as an experiment to be tried on perfons affected by breathing a poisonous vapour in old vaults, mines, deep holes or cavities under ground. Which, I am apt to think, might fave the lives of feveral, by what I have feen practifed on a dog convulfed, and in all appearance dead, but inftantly reviving on being taken out of the abovementioned Grotto and thrown into a lake adjacent.

145. Air, the general menftruum and feminary, feemeth to be only an aggregate of the volatile parts of all natural beings, which variously combined and agitated produce many various effects. Small particles in a near and close fituation strongly act upon each other, attracting, repelling, vibrating. Hence divers fermentations, and all the variety of meteors, tempefts, and concuffions both of earth and firmament. Nor is the microcofm lefs affected thereby. Being pent up in the vifcera, veffels, and membranes of the body, by it's falts, fulphurs, and elastic power, it engenders cholics, fpafms, hyfteric diforders and other maladies.

146. The specific quality of air is taken to be

I 2

permanent

permanent elafticity. Mr. Boyle is exprefly of this opinion. And yet, whether there be any fuch thing as permanently elaftic air may be doubted, there being many things which feem to rob the air of this quality, or at leaft leffen and fufpend it's exertion. The falts and fulphurs, for inftance, that float in the air abate much of it's elafticity by their attraction.

147. Upon the whole it is manifeft, that air is no diftinct element, but a mass or mixture of things. the most heterogeneous and even oppofite to each other (m), which become air, by acquiring an elafticity and volatility from the attraction of fome active, fubtile substance; whether it be called fire, æther, light, or the vital spirit of the world; in like manner as the particles of antimony, of themfelves not volatile, are carried off in fublimation and rendered volatile, by cohering with the particles of fal ammoniac. But action and reaction being equal, the fpring of this æthereal fpirit is diminished by being imparted. It's velocity and fubtilty are alfo lefs from it's being mixed with groffer particles. Hence found moves flower than light, as mud than water.

148. Whether air be only freed and fixed, or generated and deftroyed, it is certain that air begins and ceases to exert or fhew icfelf, Much by experiments feems to be generated, not only from animals, fruits, and vegetables, but alfo from hard bodies. And it is obferved by Sir Ifaac Newton, that air produced from hard bodies is moft elaftic. The tranfmutation of elements, each into other, hath been anciently held. In Plutarch we find in was the opinion of Heraclitus, that the death of fire was a birth to air, and the death of air a birth to water. This opinion is alfo maintained by (m) 137, 145.

Sir