New experiments physico-mechanical, touching the air

A Summary of the Contents of the several Chapters.

PART I.

WHerein the Adversaries Objections against the Elaterists are exa∣mined.

CHAP. I.

The occasion of this Writing, pag. 1. Franciscus Linus his civility in writing obliges the Author to the like, p. 2. Books concerning the Torricel∣lian Experiment wherewith the Author was formerly unacquainted, ibid. The Inconvenience of Linus's Principles, ibid. The division of the ensuing Treatise into three parts.

CHAP. II.

A repetition of the Adversary's Opinion and Arguments. His Argu∣ments against the Weight of the Air examined, p. 4. An Experiment of his to prove that the external Air cannot keep up twenty Inches of Quick-sil∣ver from descending in a Tube twenty Inches long, ibid. The Author's answer and reconciliation of the Experiment to his Hypothesis, p. 5. and the relation of an Experiment of the Author's, wherein only water being employed instead of Quick silver, without other alteration of the Adversaries Experiment, it agrees well with and confirms the Author's Hypothesis, and his Explication of the mentioned Experiments, ibid. That Water hath no Spring at all, or a very weak one, p. 6. The second Argument examined, ib. Whether the same quantity of Air can adequately fill a greater space, p. 7. The conceivableness of both Hypotheses compared, ibid.

CHAP. III.

Another Argument of the Adversaries, from an Experiment wherein the Mercury sinking draws the Finger into the Tube, examined. Q. Whether the Mercury placed in its own station is upheld by the external Air, or sus∣pended there by an internal Cord? p. 7, 8.

CHAP. IV.

A repetition of Franciscus Linus his principal Experiment, wherein in a Tube of twenty Inches long the Finger on the top is supposed to be strongly drawn and suck'd into the Tube, p. 8. The Experiment explicated without the assistance of Suction, by the pressure of the external Air upon the outside of the Finger, thrust, not suck'd in, p. 9. Franciscus Linus his argumen∣tation considered, p. 10.

CHAP. V.

The Eximiners last Experiment considered, in which he argues against the Author's Hypothesis, because Mercury is not suck'd out of a Vessel through a Tube so easily as Water is, p. 11, 12. An Experiment of Monsieur Paschall shewing, that if the upper part of a Tube could be freed from the pressure of all internal Air, the Mercury would by the pressure of the outward Air be carried up into the Tube as well as Water, till it had attained a height great enough to make its weight equal to that of the Atmosphere, p. 13. Why in a more forcible respiration the Mercurial Cylinder is raised higher than in a more languid, p. 14. A Remark by the bie, That the contraction of the Ad∣versaries supposed Funiculus is not felt upon the Lungs, p. 15.

CHAP. VI.

The examination of the Adversaries 4^th Chapter, p. 15. That the Spring of the Air may have some advantage in point of force above the Weight of it, p. 16. That it is unintelligible how the same Air can adequately fill more space at one time than at another, p. 17.

PART II.

Wherein the Adversaries Funicular Hypothesis is examined.

CHAP. I.

Wherein what is alledged to prove the Funiculus is considered; and some Difficulties are proposed against the Hypothesis.

The nature of this supposed Funiculus described, p. 18. That according to the Adversaries Opinion this Funiculus is produced by Nature only to binder a Vacuum, p. 19, 20. The Adversaries proofs that there is no Va∣cuum examined, p. 20, 21. That where no sensible part is un-enlightned, the place may not be full of light, p. 21. The same true in Odours, ibid. That there may be matter enough to transmit the impulse of Light, though betwixt the Particles of that matter there should be store of Vacuities inter∣cepted, p. 22. That a solid Body bath no considerable sense of pressure from fluid bodies, p. 24. Of the causes of the Vibrations of Quick-silver in its descent, p. 24, 25.

CHAP. II.

Wherein divers other Difficulties are objected against the Funicular Hy∣pothesis. As that in Liquors of divers weights and natures, as Water, Wine and Quick-silver, there should be just the same weight or strength to extend them into a Funiculus, p. 27. That whereas the Weight and Spring of the Air is inferr'd from unquestioned Experiments, the account of that Hypo∣thesis is strange and unsatisfactory. As that the Quick-silver doth not only touch the top of the Glass, but stick to it; That Nature wreaths a little rare∣fied

Air into a strong rope even able to draw up Quick-silver, p. 27, 28. That Rarefaction is performed by a certain unknown force, or vis divulsiva, ibid. That thin Surfaces are left successively one after another, that these Surfaces are contrived into strings, that may be stretch'd without being made more slender, &c. p. 29. The illustration of the manner how his Funiculus is made, from the rarefaction of Wax or Tallow in a lighted Candle, is consider∣ed, p. 30. and shewed not to be apposite, ibid. Divers other difficulties and improbabilities manifested in the Funicular Hypothesis, p. 31. Of the in∣ward Spring necessary to the contraction of his Funiculus, p. 31, 32. An Argument from a Pendulum's moving freely in an exhausted Receiver, that the medium it moves in doth not consist of innumerable exceedingly-stretch'd strings, p. 35.

CHAP. III.

The Aristotelean Rarefaction proposed by the Adversary examined. What Rarefaction and Condensation is, p. 34. Three ways of explicating how Ra∣refaction is made, p. 34, 35. Absurdities in resolving the Magdeburg Ex∣periment by the Aristotelean way of Rarefaction, p. 36. The inconveniences of the several Hypotheses compared, p. 37. The difficulties in the Adversa∣ries explaining Rarefaction by Bodies infinitely divisible, ibid. The difficul∣ties of explaining it by supposing Bodies made up of parts indivisible, p. 39, 40. The difficulties wherewith his Condensation is incumbred, as that it in∣fers Penetration of Dimensions, &c. p. 41.

CHAP. IV.

A Consideration pertinent to the present Controversie, of what happens in trying the Torricellian and other Experiments at the top and feet of Hills. That the Funicular Hypothesis is but an Inversion of the Elastical, one sup∣posing a Spring inwards, the other outwards; one performing its effects by Pulsion, the other by Traction, p. 46. That these trials on the tops and feet of Hills determine the case for the Author's Hypothesis, p. 47. The truth of the Observation of Monsieur Paschall confirmed, p. 48. and the several tri∣als that have been made of it related, ibid. A trial of the Author's from the Leads of the Abbey-Church at Westminster, p. 50, 51, 52. That the subsidence of the Mercury at the top of a Hill proceeds from the lightness of the Atmospherical Cylinder there, p. 53. The relation of an Experiment late∣ly made at Hallifax Hill in confirmation of the former, p. 54.

CHAP. V.

Two new Experiments touching the measure of the force of the Spring of the Air compress'd and dilated. That it is capable of doing far more than the necessity of the Author's Hypothesis requires, p. 55. The first Experi∣ment, of compressing Air by pouring Mercury into a crooked Tube, related, ibid. Wherein the same Air being brought to a degree of density twice as

great, obtains a Spring twice as strong as before, p. 57. A Table of the Con∣densation of the Air according to this Experiment, p. 58. Particular Cir∣cumstances observed in the making the Experiment, ibid. How far the Spring of the Air may be increased, p. 60. Of the decrement of the force of dilated Air, p. 61. A Table of the Rarefaction of the Air, p. 62. Par∣ticular Circumstances in making the Experiment whence this Table was drawn, p. 63, &c. That the free Air here below appears to be near as strong∣ly comprest by the weight of the incumbent Air as it would be by the weight of a Mercurial Cylinder of 28 or 30 Inches, p. 65.

PART III.

Wherein what is objected against Mr. Boyle's Explications of particular Experiments is answered.

The entrance into this Part of the Discourse, with an advertisement how far only it will be requisite to examine the Adversaries assertions and explica∣tions, the Hypothesis on both sides being before considered, p. 67.

A defence of the first and second Experiments, concerning the intrusion of the Finger into the Orifice of the Valve of the evacuated Receiver, p. 68.

A defence of the third Experiment, why the Sucker being drawn down there is no greater difficulty in the end than in the beginning of the depression, ibid.

Of the fourth Experiment, touching the swelling of a Bladder upon the exhaustion of the ambient Air, and proportionably to that exhaustion, p. 70, 71. The Author's and the Funicular Hypothesis in the explication of this Phaenomenon compared, ibid.

Of the fifth Experiment, ibid.

Of the eighth Experiment, about the breaking of a Glass-Receiver which was not globular upon the exhaustion of the inward Air, p. 71. Whether it were more likely to be broken by the pressure of the Atmosphere without, or a contraction of a string of Air witbin, p. 72.

Of the ninth Experiment, ibid. Whether the breaking of the Vial out∣wards in the exhausted Receiver, was caused by the pressure of the Atmosphere through the Tube which was open to the ambient Air, p. 73.

Of the 17. Experiment, p. 74, 75, 76. The Torricellian Experiment being made within the Receiver, whether the descent and ascent of the Mercury in the Tube, under and above its wonted station, be caused by the debili∣tated and strengthned Spring of the Air, ibid.

Of the 18. Experiment, p. 77, 78. Whether the Authors or the Funi∣cular Hypothesis assign the more probable cause why a Cylinder of Mercury did in Winter rise and fall in the Tube, sometimes as Water in a weather-glass

according to the laws of Heat and Cold, and sometimes contrary there∣unto, ibid.

Of the 19. Experiment, p. 79.

Of the 20. Experiment, p. 79, 80. Some mistakes in the Adversary of the Author's meaning about the Spring of the Water, and the places whence the bubbles arose, ibid. The Hypotheses compared, ibid.

Of the 31. Experiment, p. 81, 82, 83. Of the cause why the Marbles fell not asunder in the exhausted Receiver, though a weight of four Ounces were hung at the lower stone, ibid. Whether the account of the Author or Adversary be more satisfactory, ibid.

Of the 32. and 33. Experiments, of the re-ascent of the Sucker and its carrying up a great weight with it upon the exhaustion of the Receiver, p. 84. How the flesh and neighbouring blood of a Patient is thrust up into a Cup∣ping-glass, ibid.

Of the 37. Experiment, and the cause of the appearance of light or white∣ness therein, p. 85.

Of the 40. and 41. Experiments, concerning the cause of the sudden death of Animals in the exhausted Receiver, p. 85, 86.

Of the 42. and 43. Experiments, p. 87.

The Conclusion, p. 91, 92.

FINIS.