an ofcillatory motion, and properly modified, fo as to communicate the like motion to one part of the body, the ear only, hath fuch good and great effects: Then if a certain quantity of air could have a tremulous motion produced therein, of fuch a ftrength and force as to shake and agitate the whole animal machine, and communicate the like motion not only to the ear (which in fuch case must be fecured, by a proper contrivance, from being damaged) but to the whole body, and all its parts, that this would prove one of the moft perfect kinds of exercife, for preferving health, and curing difcafes; this the author calls Mechanical mufic, in contradiction to ordinary foft mufic, the first being intended to be raised to such a pitch and ftrength, as to caufe the whole nervous fyftem, and all parts of the body, to vibrate fenfibly from its furface to the very axis. The author, induced from the aforefaid confiderations, proceeds to the folution of this molt ufeful phyfical problem:

PROBLEM.

89. Wherein fome general principles are propofed, for conftructing an artificial atmosphere, or air-chamber, whereby a certain quantity of air may be put into a strong vibrative motion; and as the human body is a compreffible machine, compofed of folids extremely fenfible and elaftic, upon its being placed in the focus of fuch an artificial phonic machine, or air-chamber, having the air therein agitated like to a violent vortex, the whole body, both folids and fluids, will become affected with an ofcillatory motion of fyftole and diastole, beginning at the furface, and propagated to the very axis of the body, from whence the motion will be reflected outwards to the furface; and thus all parts of the body will contract and dilate fucceffively with great velocity, whilft it is fubject to this kind of motion and exercise from the air.

90. That the whole animal fyftem will receive great benefit hereby is evident; and first, as to the folds, by the ftrong quick tremors and concuffions produced therein, fuch parts as are unfit to be retained in their texture and compofition, as being either worn out, or unaflimilable with the structure of the animal fibres, will be thereby separated, difengaged, and caft out, and room made for the attraction and reception of other particles of a more homogeneous nature in their places; wherein confifts the perfect nutrition of the folids. And as the folids will be greatly benefited by this moft falutary exercife, the fluids, by confequence, will have their qualities greatly improved at the fame time, by having their vifcidity and cohefion diffolved, and rendered more fluxil, and paffable through the glands, and thereby prove the beft means for preferving health, and curing difeafes. That the effects, produced by fuch quick tremulous pulfations, impreffed thus upon the whole nervous fyftem, and animal machine, muft be furprizingly great for attaining both these intentions, is demonftrable from the principles of animal mechanifm, and the laws relating to the communication of motion to elaftic bodies (as is the human) by preffure, impulfe, percuffion, &c. of which the author gives, for inttance, the famous cafe relating to the cure of the poifon of the Tarantula, which can be ac counted for from these principles only.

91. The author concludes this Chapter with a fhort account of the cause of electricity, and its ufe in curing difeafes; which may be

fumm'd

fumm'd up in the following obfervations: That the earth attracts hte fluids of light and air, wherewith it forms to itself an atmosphere, the denfity, weight, elafticity, &c. whereof increase the nigher to its furface, where the attraction is ftrongeft, and decrease in receding therefrom, until they are loft, and vanish into the general medium of elementary fire, or ether, diffused throughout the folar fyftem. This terrestrial atmosphere (confifting chiefly of elementary fire and air, with the exhalations iffuing from the earth) like to a warm, fluid, elastic mould, ftrongly embracing and compreffing the whole furface of the earth, ferves to keep the fame in a continual vibrative motion, and endow'd with proper degrees of warmth, whereby it becomes a proper nidus and habitation for the generation and growth of animals, &c. Juft fo, in like manner, every individual animal, vegetable, or other body, as well as the earth, has each a proper fphere of attraction, within which the fluids of elemental fire and air being accumulated, and condensed, form round every body a diftinct atmosphere, fo much the more denfe and elaftic, the nigher to the body, and diminishing in receding therefrom, until it becomes of the fame denfity with the ge. neral atmosphere, and makes part thereof. This particular atmosphere (confifting chiefly of ethereal fire and air, together with the effluvia iffuing out of the body) peculiarly belonging to each body, is of different extents, denfities, and qualities, in proportion to the attractive powers and properties inherent in each fpecies of bodies; which atmosphere, like a warm, fluid, elastic, heavy mould, or covering, every where enveloping and strongly compreffing every body, ferves to keep it in a conftant vibratory motion, and poffefs'd with proper degrees of heat, and in a conftant progreffive mutation from one state to another.

92. These principles afford the most natural account of all the furprizing phenomena of attraction and repulfion, &c. exhibited by electric bodies, when excited to action, which appear to be wholly ow ing to a brifk vibrative motion, produced in the particles of the electric body by attrition, whereby having their heat and attractive power increafed, the atmosphere of the electric body, being now more ftrongly impregnated with the fluid of fire, and the effluvia of the electric body, becomes agitated, like a violent vortex, with a quick vibrative motion. And as all bodies have their particular atmosphere, confifting of fire, air, &c. if a number of bodies be placed continuous, or contiguous to one another, and one of the faid bodies be brought within the atmosphere of the electric body, when folicited to action, the atmofpheres of all the other bodies will become agitated with the like ofcillatory vibrative motion, which will be propagated, like a cylindrical vortex, through the whole series of bodies, to a great distance, in all directions, and with great velocity, like firing a train of gunpowder, or just as any number of candles, newly extinguished, being placed at proper diftances, and in any order and directions, will become all lighted, by bringing a lighted candle within the atmosphere of any one of them. From thefe principles all the phenomena of electricity may be rationally folved, without having recourfe to any fictitious fluid, or any emanation of effluvia, which may be call'd fpecifically and properly electrical, flowing out of the electrical body itself.

93. Electricity being now the fubject of general enquiry, it may be necessary to offer some further observations, thewing this power to have

been

been in conftant action from the beginning of the world, and to exercife its influence upon the earth, and all bodies within the solar system, as will be evident from the following confiderations.

94. The earth being an oblate fpheroid, revolves, together with the atmosphere, about its axis once in twenty four hours, at the rate of about 1600 feet in one fecond of time. By the conftant action of the Sun, that immenfe body of concentrated fire, the fluid of elementary fire, light or ether, diffused every where, is continually agitated with an intense vibrative motion, propagated fucceffively therein, with inconceivable velocity, and to immenfe diftances, and directed in rectilineal rays or streams, ferving to warm and enlighten the whole fyftem. As the earth, by the diurnal motion, prefents the feveral parts of its furface fucceffively to the Sun, they receive a brifk vibratory motion from the ftreams and rays of light impinging thereon, (as may be plainly feen by looking horizontally upon the earth's furface, when the Sun fhines thereon in the fummer) fo that the furface of the earth, from its extream fwift motion, and the attrition it receives from the impulses of the rays of light falling thereon, becomes thereby continually excited and put into a state of electricity, juft in like manner as the artificial glafs fpheroid, ufed for exhibiting the phenomena of olectricity, in experimental courfes. But as the velocity of the earth's diurnal motion is vaftly greater than can be given to any artificial glass fphere, its electrical force and effects, fo far as they depend upon the velocity of motion, must be proportionally greater alfo; and here likewife the velocity of the earth's annual progreffive motion in its orbit may be confidered as a conjunct co-operating cause.

95. From these principles it is manifeft the earth is in a continual ftate of exerting and communicating the power of electricity to the whole terrestrial atmosphere, and to all bodies upon its furface, which power, thus univerfally diffufed, ferves as a general ferment and cause of action, whereby all bodies are kept in a conftant ofcillatory motion, and difpofed to undergo thefe changes neceffary to their generation, growth, and corruption. And this furnishes us with the most natural principles for explicating many of the most abftruse appearances in nature, as the generation of meteors, vapours, exhalations, thunder, lightning, ignes fatui, aurora borealis, winds, water-fpouts, tails of comets, &c.

96. The earth being in a perpetual ftate of exerting and communicating electricity, all animals and vegetables are constantly more or lefs electrified thereby. And befides, all animal bodies are naturally, of themselves, conftantly in a state of exerting and communicating electricity, more or lefs, from the vital force and action, with the vibrative motion of their parts; which principles furnish the most natural account of those fingular inftances of fympathy and antipathy, or attraction and repulfion, which fome perfons have to certain objects, and why yawning is catching; as alfo for that kind of vital fire, phosphorus, or electricity, obfervable in the glow-worm, and in the eyes of fome animals, as cats, rattlefnakes, &c. by which the latter are faid to fascinate, or rather electrize their prey; and likewife the force of the mother's imagination in marking the fœtus, &c.

97. To obviate an apparent objection to this doctrine, it may be

ne

neceffary to observe, that, as there are no bodies perfectly elaftic or unclaftic, and as the laws relating thereto hold true only in proportion as the bodies partake more or less of these two properties, fo in like manner, neither the earth, atmosphere, or any animal, are perfectly elastic or non elastic bodies, but partaking of these two oppofite qualities in different degrees, whereby providence, as in all other things, hath wifely temper'd and reftrain'd the power of the earth's electricity (by a juft alloy of its oppofite quality) within fuch limits as are neceffary and compatible with animal life, fo that its effects, tho' both constant and neceflary to animals, are not however fo ftrong (excepting in particular cafes) as to be fenfible, or difturb their natural quiet and cafe.

98. The principles here advanced, of the earth's being in a continual ftate of exerting and communicating electricity to all bodies upon its furface, appears moreover to fuggeft fome probable hypothefis for difcovering the cause of magnetism; as both these powers may probably be found to have fome mutual relation and connexion; the earth being both the great electrical, as well as the great magnetical Spheroid.

99. The author, from confidering the fenfible effects, and ftimulating force, which the fluids of light and air acquire, upon their being properly modified. and put in motion by electric bodies when excited, takes occafion to propofe a new mechanical method, which will be of real ufe and efficacy in the cure of wounds, ulcers, paralytic, and other topical ailments, &c. For as much as all bodies, when heated, either by attrition, &c. emit effluvia (which however, as has been obferved, are not the fole cause of those effects call'd electrical) which, when copiously rais'd and emitted by ftrong friction, are ever accompanied with an intense vibrating motion, impreffed at the fame time upon the fluids of light and air, if fuch bodies, especially those of the refinous, fulphureous kind, &c. when ftrongly rubbed and excited, are applied or brought near to any diseased part, and have their power renew'd from time to time, as it becomes destroy'd or weakened, and kept thus froth apply'd to the part for a proper time, and at due intervals, the fmart vibrations which will be communicated to the ailing part, by the effluvia ifiuing from the refinous electric body, together with the pungent ftimulating force imprefied thereon by the fluids of light and air, when thus modified by the electric body, will ferve as a dry vapour-bath, and contribute greatly to reftore the loft tone and elafticity of the animal folids, and thereby enable them to fubdue and overcome the incumbrance laid thereon by the vifcid, ftagnant humours, &c. The reafon of these falutary effects is demonftrable from the laws of the animal economy, and the mechanifm and ftructure of the animal fibres, with the nature of stimuli, and the great and contrary effects which thofe of the grateful, and dolorific kind, are capable of producing in the organs of fenfation.

The fubject of this chapter, with the arguments and obfervations advanced in fupport thereof, appear to afford a very extenfive rational plan for many great improvements in the practice of phyfic, and as fuch, merit the moft ferious attention and encouragement of the public.

СНАР.

I CO.

TH

CHA P. VI.

HE author obferves that, as in most diseases the fluids are determined in unequal quantities and velocities upon the parts, occafioned by fome of the organs having their moving force rais'd or lower'd more than is natural thereto, which is the caufe of most, if not all, difeafes (No. 13, 17.) whereby the equilibrium and just balance of motion between the organs being loft, the fluids become circulated irregularly; confequently, in order to restore this loft balance of motion, there are two general indications to be purfued in the cure of moft or all diseases; namely, derivation and revulfion. Thus in tumors, when fuppuration is proper to be forwarded, alfo in paralytic cafes, and the fuppreffion of any natural evacuation, &c. in fuch cafes a derivation of the fluids to the parts affected is indicated; but in all cafes attended with too great an afflux of the fluids to fome part, as the head, or upper region, as in apoplexies, hydrocephalies, inflammations of the brain or its meninges, opthalmies, quinfies, pleurifies, hemorrhages from the fuperior parts, &c. revulfion is neceffary, by causing the fluids to move in lefs quantities to the affected organs, and turning their courfe downwards. So that there is fcarce any difeafe, wherein the phyfician will not be obliged to ufe either derivation or revulfion. And the practice of furgery confifts chiefly in a judicious execution of these two general intentions; thus in the cure of wounds, tumors, ulcers, inflammations, gangrenes, gonorrheas, hemorrhages, amputations, ruptures, fractures, diflocations, &c. as the ailing parts are weakeft, there will be a greater fluxion of the humours thereto; confequently the cure depends in a manner wholly upon revulfion, and that is belt effected by due evacuation, but chiefly by proper bandage; and as the good effects of all bandage confift wholly in the additional preffure being equably apply'd, and in a proper quantity, whereby it contracts the parts, and thereby ftrengthens and enables them to refift the influx of the humours; confequently, if preffure can be apply'd in any degree required, to the body or its members, either by air or water, &c. the preffure thus produced by the application of a fluid, being more equable and uniform, and capable of being regulated in any quantity, must be infinitely more efficacious and fuccefsful in moft cafes, for effecting a revulfion of the fluids, than any folid bandage and comprefs, which, tho' performed with the greatest judgment and dexterity, will notwithstanding fill act with unequal preffure upon the part, and thereby occafion both pain and fluxion. Accordingly the author, in confequence of the aforefaid reafoning, propofes fome new methods and machines for applying preffure in any degree required, by means of air or water, to the feveral regions and members of the body, as alfo vapour-baths both humid and dry, &c. whereby these two cardinal, principal indications of derivation and revulfion, will be effected in the most perfect manner: a fuller account whereof, with the draughts and defcription of the machinery relating thereto, may be found in the original book.

CHAP.