213. The vivifying luminous æther exifts in all places, even the darkeft caverns, as is evident from hence, that many animals fee in thofe dark places, and that fire may be kindled in them by the collifion or attrition of bodies. It is alfo known that certain perfons have fits of feeing in the dark. Tiberius was faid to have had this faculty or diftemper. I my felf knew an ingenious man, who had experienced it feveral times in himself. And doctor Willis, in his tract De fanguinis ac cenfione, mentions another of his own knowledge. This luminous æther or fpirit is therefore said by Virgil, to nourish or cherish the innermoft earth, as well as the heavens and celeftial bodies. Principio cœlum ac terras, campofque liquentes, Lucentemque globum Lunæ, Titaniaque aftra Spiritus intus alit. 214. The principles of motion and vegetation in living bodies feem to be delibations from the invifible fire or spirit of the universe (a). Which, though present to all things, is not nevertheless one way received by all; but variously imbibed, attracted, and fecreted by the fine capillaries, and exquisite strainers in the bodies of plants and animals, whereby it becomes mixed and detained in their juices. 215. It hath been thought by fome observers of nature, that the fine glandular veffels admit from the common mafs of the blood, only fuch juices as are homogeneous to thofe, with which they were originally imbued. How they came to be fo imbued doth not appear. But thus much is plain; that fine tubes attract fluids, that the glands are fine tubes, and that they attract very (a) 43, 157, 164, 171. N 2 diffe different juices from the common mafs. The fame holds alfo with regard to the capillary veffels (a) of vegetables, it being evident that through the fine strainers in the leaves and all over the body of the plant, there be juices or fluids of a particular kind drawn in, and feparated from the common mass of air and light. And that the most elaborate fpirit, whereon the character or diftinguifhing virtue and properties of the plant depend, is of a luminous (b) and volatile nature, being loft or escaping into air or æther, from effential pils and odoriferous waters, without any fenfible diminution of the fubject. 216. As different kinds of fecreted light or fire produce different effences, virtues, or fpecific properties, fo alfo different degrees of heat produce different effects. Thus one degree of heat keeps the blood from coagulating, and another degree coagulates the blood. Thus a more violent fire hath been obferved to fet free and carry off that very light, which a more moderate fire had introduced and fixed in the calcined regulus of antimony. In like manner, one kind or quantity of this ætherial fiery fpirit may be congenial and friendly to the fpirits of a man, while another may be noxious. 217. And experience fheweth this to be true. For the fermented fpirit of wine or other liquors produceth irregular motions, and fubfequent depreffions in the animal fpirits. Whereas the luminous fpirit lodged and detained in the native balfam of pines and firs, is of a nature fo mild and benign and proportioned to the human constitution, as to warm without heating, to cheer but not ine(a) 30, 31, 33, 35. (6) 37, 43. briate, briate, and to produce a calm and steddy joy like the effect of good news, without that finking of fpirits which is a fubfequent effect of all fermented cordials. I may add, without all other inconvenience, except that it may, like any other medicine, be taken in too great a quantity for a nice ftomach. In which cafe it may be right, to leffen the dose, or to take it only once in the four and twenty hours, empty, going to bed (when it is found to be leaft offenfive) or even to fufpend the taking of it for a time, till nature fhall feem to crave it, and rejoice in it's benign and comfortable spirit. 218. Tar-war ferving as a vehicle to this fpirit is both diuretic and diaphoretic, but feems to work it's principal effect by affifting the vis vitæ, as an alterative and cordial, enabling nature by an acceffion of congenial fpirit, to affimilate that which could not be affimulated by her proper force, and fo to fubdue the fomes morbi. And this fhould fem in moft cafes the best and safest course. Great evacuations weaken nature as well as the disease. And it is to be feared that they who use falivations and copious bleedings may, though they should recover of the diftemper, in their whole life be never able to recover of the remedies. 219. It is true indeed, that in chronical cafes there is need of time to compleat a cure, and yet I have known this tar-water in diforders of the lungs and ftomach to prove a very speedy remedy, and to allay the anxiety and heat of a fever in an inftant, giving eafe and fpirits to the patient. This I have often experienced, not without furprife, at feeing thefe falutary effects follow fo immediately in a fever on taking a glass of tar-water. Such is the force of thefe active vivifying principles contained in this balfam, 220. Force 220. Force or power, ftrickly speaking, is in the agent alone who imparts an equivocal force to the invifible elementary fire, or animal fpirit (a) of the world, and this to the ignited body or vifible flame, which produceth the fenfe of light and heat. In this chain the first and laft links are allowed to be incorporeal: the two intermediate are corporeal, being capable of motion, rarefaction, gravity, and other qualities of bodies. It is fit to distinguish these things, in order to avoid ambiguity concerning the nature of fire. 221. Sir Ifaac Newton in his Optics, afks; Is not fire a body heated fo hot as to emit light copiously for what elfe, adds he, is a red-hot iron than fire? Now it fhould feem, that to define fire by heat, would be to explain a thing by it felf. A body heated fo hot as to emit light is an ignited body, that is, hath fire in it, is penetrated and agitated by fire, but is not itself fire. And although it fhould in the third foregoing acceptation, or vulgar fenfe pafs for fire, yet it is not the pure elementary (b) fire in the fecond or philofophic fenfe, fuch as was understood by the fages of antiquity, and fuch as is collected in the focus of a burning glafs; much lefs is it the vis, force, or power of burning, deftroying, calcining, melting, vitrifying, and raifing the perceptions of light and heat. This is truly and really in the incorporeal agent, and not in the vital spirit of the universe. Motion, and even power in an equivocal fenfe, may be found in this pure æthereal spirit, which ignites bodies, but is not itself the ignited body, being an inftrument or medium (c) by which the real agent doth operate on groffer bodies. (a) 153, 156, 157. (b) 190. (c) 160. 222. It 222. It hath been fhewed in Sir Ifaac Newton's Optics, that light is not reflected by impinging on bodies, but by fome other caufe. And to him it feems probable, that as many rays as impinge on the folid parts of bodies, are not reflected but ftifled and retained in the bodies. And it is certain, the great porofity of all known bodies affords room for much of this light or fire to be lodged therein. Gold itself, the most folid of all metals, seems to have far more pores than folid parts, from water being preffed through it in the Florentine experiment, from magnetic effluvia passing, and from mercury entering its pores fo freely. And it is admitted that water, though impoffible to be compreffed, hath at least forty times more pores than folid parts. And as acid particles, joined with those of earth in certain proportions, are fo closely united with them, as to be quite hid and loft to all appearance, as in mercurius dulcis and common fulphur, so alfo may we conceive the particles of light or fire to be abforbed and latent in groffer bodies. 223. It is the opinion of Sir Ifaac Newton, that fomewhat unknown remains in vacuo, when the air is exhaufted. This unknown medium he calls æther. He fuppofeth it to be more fubtil in its nature, and more-fwift in its motion, than light, freely to pervade all bodies, and by its immense elafticity to be expanded throughout all the heavens. Its denfity is fuppofed greater in free and open spaces, than within the pores of compact bodies. And, in paffing from the celeftial bodies to great distances, it is fuppofed to grow denfer and denfer continually; and thereby caufe those great bodies to gravitate towards one another, and their respective parts towards their centers, every body |