3. That, if a Body, contiguous to the Water, be altogether, or in part,
lower than the highest level of the said Water, the lower part of the Body
will be pressed upward by the Water, that touches it beneath.
4. That in the Ascension of Water in Pumps, &c. there needs nothing to
raise the Water, but a Competent weight of an External Fluid.
5. That the pressure of an External Fluid is able to keep an Heterogeneous
Liquor suspended at the same height in several Pipes, though these Pipes be
of very different Diameters.
{175}
6. If a Body be placed under Water, with its uppermost Surface parallel to
the Horizon; how much Water soever there may be on this or that side above
the Body, the direct pressure susteined by the Body (for we now consider
not the Lateral nor the Recoyling pressure, to which the Body may be
exposed, if quite environed with Water) is no more, than that of a Column
of water, having Horizontal Superficies of the Body for its Basis, and the
Perpendicular depth of the Water for its height.
And so likewise,
If the Water, that leans upon the Body, be contained in Pipes open at both
ends, the pressure of the Water is to be estimated by the weight of a
pillar of Water, whose Basis is equal to the lower Orifice of the Pipe
(which we suppose to be parallel to the Horizon) and its height equal to a
perpendicular, reaching thence to the top of the Water; though the Pipe be
much inclined towards the Horizon, or though it be irregularly shap'd, and
much broader in some parts, than the said Orifice.
7. That a Body, immersed in a Fluid, sustains a Lateral pressure from the
Fluid; and that increased, as the depth of the immersed Body, beneath the
Surface of the Fluid, increaseth.
8. That Water may be made as well to depress a Body lighter than it self,
as to buoy it up.
9. That, whatever is said of Positive Levity, a parcel of Oyl lighter than
Water, may be kept in Water without ascending in it.
10. That the cause of the Ascension of Water in Syphons, and of its flowing
through them, may be explicated without having a recourse to Nature's
abhorrency of a _Vacuum_.
11. That a Solid Body, as ponderous as any yet known, though near the Top
of the water it will sink by its own weight; yet if it be placed at a
greater depth, than that of twenty times its own thickness; it will not
sink, if its descent be not assisted by the weight of the incumbent Water.
These are the _Paradoxes_, evinced by our Authour with much evidence and
exactness, and very likely to invite Ingenious men to cultivate and to make
further disquisitions in so excellent a part of Philosophy, as are the
_Hydrostaticks_; and Art deserving great _Elogiums_, not only, upon the
account of the _Theorems_ and _Problems_, which are most of them pure and
handsome productions of Reason, very delightful and divers of them
surprising, and besides, much conducing to the clear explication and {176}
thorow-understanding of many both familiar and abstruse _Phaenomena_ of
Nature; but also, upon the score of its _Practical_ use, since the
Propositions, it teaches, may be of great importance to Navigation, and to
those that inquire into the Magnitudes and Gravities of Bodies, as also to
them, that deal in Salt-works: Besides, that the _Hydrostaticks_ may be
made divers waies serviceable to _Chymists_, as the Author intimates, and
intends to make manifest, upon several occasions, in his yet unpublisht
part of the _Usefulness of Natural and Experimental Philosophy_.
These Propositions are shut up by two important _Appendixes_, whereof the
_one_ contains an Answer to seven Objections by a late learned Writer, to
evince, that the upper parts of water press not upon the lower; the
_other_, solves that difficult _problem_, why _Urinators_ or _Divers_, and
others, who descend to the bottom of the Sea, are not oppressed with the
weight of the incumbent water? where, among other solutions, _that_ is
examined, which occurs in a printed Letter of Monsieur _des Cartes_, but is
found unsatisfactory.
II. _Nicolai Stenonis de Musculis & Glandulis Observationum Specimen; cum
duabus Epistolis Anatomicis_. In the _Specimen_ it self, the Author, having
described in _general_, both the _Structure_ and the _Function_ of the
_Muscles_, applies that description to the _Heart_, to demonstrate that
_that_ is also a _true Muscle_: Observing _first_, that in the substance of
the _Heart_ there appears nothing but _Arteries, Veins, Nerves, Fibres,
Membrans_; and that that, & nothing else is found in a _Muscle_; affirming
withall, that which is commonly taught of the _Muscles_, and particularly
of the _Heart's Parenchyma_, as distinct from _Fibres_, is due, not to the
_Senses_, but the _Wit_ of _Anatomists_: so that he will not have the
_Heart_ made up of a substance peculiar to it self, nor considered as the
principle of _Innate heat_, or of _Sanguification_, or of _vital spirits_.
He observes _next_, that the _Heart_ performs the like _operation_ with the
_Muscles_, to wit, to contract the Flesh; which action how it can have a
different cause from that of the Contraction made in the _Muscles_, where
there is so great a parity and agreement in the _Vessels_, he sees not. And
as for the _Phaenomena_, that occur, of the _Motion_ of the Heart, he
undertakes to explicate them all, from the _Ductus_ or _Position_ of the
_Fibres_; but refers for the performance of this undertaking to another
_Treatise_, he intends to publish.
[Sidenote: __Conglobate_ Glanduls are called those, that do consist, as it
were, of one continued substance, having an _even_ superficies; whereof
there are many in the _Mesentery_, and in other places: contra distinguisht
to those, that bear the name of _Conglomerate_ Glanduls, which are made up
of several small Kernels, such as the _Pancreas_, the _Salivating
Glanduls_, &c._]
As to his Observations about _Glanduls_, he affirms, that he has been the
First, that has discover'd that Vessel, which by him is call'd {177}
_Salivare Exterius_, passing from the _Parotides_ (or the two chief
Arteries that are on the right and left side neer the Throat) into the
Mouth, and conveying the _Spittle_: Where he also gives an account of
several other Vessels and Glanduls, some about the _Lips_; others under the
_Tongue_; others in the _Pallate_ &c. To which he adds the Vessels of the
_Eye-lids_, which have their root in the _Glanduls_ that are about the
Eyes, and serve for the _shedding of Tears_. He mentions also several
things about the _Lymphatick vessels_, and is of opinion, that the
knowledge thereof may be much illustrated by that kind of _Glanduls_ that
are called _Conglobatae_, and by their _true_ insertion into the veins; the
mistake of the latter whereof, he conceives to have very much misled the
Noble _Ludovicus de Bills_, notwithstanding his excellent method of
_dissection_. And here he observes _first_, that all the _Lymphatick
vessels_ have such a commerce with the _Glanduls_, that none of them is
found in the body, which either has not its origine _from_, or is inserted
_into_ a _Glandule_: And _then_, that _Glanduls_ are a kind of _Strainers_,
so form'd, that whilst the Blood passes out of the Arteries into the Veins
through the small _Capillary_ vessels, the _Serous_ parts thereof, being
freed from the _Sanguineous_, are by vertue of the beat expell'd through
fit pores into the _Capilaries_ of the _Lymphaticks_, the direction of the
_Nerves_ concurring.
Of the two annex'd _Epistles_, the _First_ gives an account of the
dissection of two _Raja's_ or _Skates_, and relates that the Author found
in the bellies of these Fishes a _Haddock_ of 11/2 span long, and a _Sole_, a
_Plaise_, and nine middle-sized _Sea crafishes_; whereof not only the three
former had their flesh, in the fishes stomack, turn'd into a _fluid_, and
the Gristles or Bones into a _soft_ substance, but the _Crafishes_ had
their shels comminuted into very small particles, tinging here and there
the _Chyle_ near the _Pylorus_; which he judges to be done not so much by
the heat of the Fishes stomack, as by the help of some digesting juyce.
Coming to the _Uterus_ of these Fishes, he takes occasion to examine, with
what ground several famous _Naturalists_ and _Anatomists_ have affirm'd,
that Eggs are the _uterus_ exposed or ejected out of the body of the
Animal. Taking a view of their _Heart_, he there finds but _one_ ventricle,
and discourses of the difficulty arising from thence. As for the _Lungs_,
he saw no clearer footsteps of them in these, than he had done in other
Fishes: but within the mouth he trac'd several _gaping fissures_, and found
the recesses of the _Gills_ so form'd, that the water taken in at the
mouth, being let out by these dores, cannot by them re-enter, by reason of
a skin outwardly passing over every hole, and covering it. Where he
intimates, that though Fishes have not _true_ Lungs, yet they want not a
_Succedaneum_ thereto, to wit, the _Gills_; and if _water_ may be to
Fishes, what _Air_ is to terrestrial Animals, for Respiration: affecting,
that whereas nothing is so necessary for the conservation of Animal life as
a reciprocal Access and Recess of the _Ambient_ to the sanguineous vessels,
tis all one, whether that be done by receiving the Ambient _within_ the
body, or by its gentle passing _by_ the _Prominent_ vessels of the _Gills_.
The other _Epistle_, contains some Ingenious Observations, touching the
way, by which the Chicken, yet in the shell, is nourish't, _videl._ not by
the conveyance of the _Yolk_ into the _Liver_ by the _Umbilical_ vessels,
nor into the _Stomack_ by the {178} _Mouth_, but by a Peculiar _ductus_, by
him described, into the _Intestins_, where, according to his alledged
experience, it is turn'd into _Chyle_: which he affirms, he hath
discover'd, by taking an Egge from under a brooding Hen, when the Chicken
was ready to break forth, and when he was looking for the passage of the
_Yolk_, out of its integument into the _Liver_, by finding it pass thence
into the _Intestins_, as he found the _White_ to do by the _mouth_ into the
_belly_. Whence he inclines to infer, that, since every _faetus_ takes in at
the mouth the liquor it swims in, and since the Chicken receives the
_white_ of the Egge into the _mouth_, and the _yolk_ by the new discover'd
_ductus_ into the _Intestins_, it cannot be certainly made out, that a
_part_ of the _Chyle_ is conveyed into the _Liver_, before it passes into
the _Heart_; Exhorting in the mean time the _Patrons_ of the _Liver_, that
they would produce Experiments to evince their Ratiocinations.
III. _Regneri de Graeff, de Succi Pancreatici Natura & usu, Exercitatio
Anatomico-medica._ In this Tract, the Industrious Author, after he has
enumerated the various opinions of _Anatomists_ concerning the use of that
kernelly substance; call'd _Pancreas_ (in _English_, the _Sweetbred_)
endeavours to prove experimentally that this _Glandule_ was not form'd by
Nature, to separate any _Excrementitious_ humor, and to convey it into the
_Intestins_, but to prepare an _useful_ juyce out of the Blood and Animal
Spirits, of a somewhat _Acid_ taste, and to carry the same into the Gut,
call'd _Duodenum_, to be there mixt with the Aliment, that has been in some
degree already fermented in the Stomack, for a further fermentation, to be
produced by the conflux of the said acid _Pancreatick_ juyce and some
_Bilious_ matter, abounding with volatile Salt, causing an Effervescence;
which done, that juyce is, together with the purer part of the nourishment,
carried into the _Milkie_ veins, thence into the _common receptacle_ of the
_Chyle_ and _Lymphatick liquor_, and so through the _ductus Thoracicus_
into the right Ventricle of the Heart.
This Assertion, first advanced (saith the _Author_) partly by _Gothofredus
Mobius_, partly by _Franciscus de le Boe Sylvius_, he undertakes to prove
by experiments; which, indeed, he has with much industry, tried upon
several Animals, to the end that he might collect some of this juyce of the
_Pancreas_ for a taste: which having at last obtained, and found it
somewhat _acid_, he thereupon proceeds to deliver his opinion both of the
_constitution_ and quantity of this _Succus_ in _healthy_ Animals, and the
vices thereof, in the _unhealthy_: deriving most diseases _partly_ from its
too great Acidity, or from its saltness, or harshness; _partly_ from its
paucity or redundancy: but especially, endeavouring to reduce from thence,
as all _intermittent Feavers_ (of all the _Phaenomena_ whereof he ventures
to assign the causes from this _Hypothesis_) so also the _Gout, Syncope's,
Stranguries, Oppilations, Diarrhaeas, Dysenteries, Hysterical_ and _Colick
passions_, &c. All which he concludes with mentioning the waies and
remedies to cure the manifold peccancy of this juyce by Evacuations and
Alterations.
This seeming to be a _new_ as well as a _considerable_ discovery, it is
hop'd, that others will by this intimation be invited to prosecute the same
by further experiments, either to confirm what this Author has started, if
true, or to rectifie it, if he be mistaken.
* * * * *
_NOTE._
In _Fig._ 1. of _Num._ 9 of these Tracts the Graver hath placed the bended
_end_ of the _Springing Wire_ C F, above the _Wire-staple_ B, between it
and the _Ring_ E, of the _Weight_ D; whereas _that_ end should have been so
expressed, as to pass _under_ the _Wire-staple_, betwixt its two Wires,
into the said _Ring_.
* * * * *
_London_, Printed for _John Martyn_, and _James Allestry_, Printers to the
Royal Society. 1666.
{179}
* * * * *
_Num._ 11.
PHILOSOPHICAL
_TRANSACTIONS._
* * * * *
_Munday_, _April._ 2. 1666.
* * * * *
The Contents.
_A Confirmation of the former Account, touching the late _Earth-quake_
near _Oxford_, and the Concomitants thereof, by Mr. _Boyle_. Some
Observations and Directions about the _Barometer_, communicated by the
same Hand. General Heads for a _Natural History_ of a Country, small or
great, proposed by the same. An Extract of a Letter, written from
_Holland_, about _Preserving Ships from being Worm-eaten_. An Account
of Mr. _Boyle's_ lately publish't Tract, entituled, _The Origine of
Forms and Qualities_, illustrated by Considerations and Experiments._
* * * * *
_A Confirmation of the former Account touching the late _Earth-quake_ near
_Oxford_, and the Concomitants thereof._
This Confirmation came from the Noble Mr. _Boyle_ in a Letter, to the
_Publisher_, as followeth:
[Sidenote: * _See_ Num. 10. Phil. Transactions p. 166-171; _at the time of
the printing whereof, this Relation of Mr._ Boyle _was not yet come to
hand._]
As to the _Earth-quake_, your curiosity about it makes me sorry, that,
though I think, I was the first, that gave notice of it to several of the
_Virtuosi_ at _Oxford_; yet the Account, that I can send you about it, is
not so much of the _Thing_ it self, {180} as of the _Changes of the Air_,
that accompanied it. To inform you of which, I must relate to you, that
riding one Evening somewhat late betwixt _Oxford_ & a Lodging, I have at a
place, 4 miles distant from it, the weather having been for a pretty while
Frosty, I found the Wind so very cold, that it reduced me to put on some
defensives against it, which I never since, nor, if I forget not, all the
foregoing part of the Winter was obliged to make use off. My unwillingness
to stay long in so troublesome a Cold, which continued very piercing, till
I had got half way home-ward, did put me upon galloping at no very lasy
rate; and yet, before I could get to my Lodgings, I found the Wind turned,
and felt the Rain falling; which, considering the shortness of the time,
and that this Accident was preceded by a setled Frost, was surprising to
me, and induced me to mention it at my return, as one of the greatest and
suddainest Alterations of Air, I have ever observ'd: And what changes I
found, have been taken notice of in the _Gravity_ of the _Atmosphere_ at
the same time by that Accurate Observer * Dr. _Wallis_, who then suspected
nothing of what follow'd; as I suppose, he has ere this told you himself.
Soon after, by my guess about an hour, there was a manifest _Trembling_ in
the House where I was (which stands high in comparison of _Oxford_.) But it
was not there so great, but that I, who chanced to have my thoughts busied
enough on other matters, than the weather, should not have taken notice of
it as an _Earth-quake_, but have imputed it to some other cause, if one,
that you know, whose hand is employed in this Paper, and begins to be a
diligent observer of Natural things, had not advertis'd me of it; as being
taken notice of by him and the rest of the people of the House. And soon
after there hapned a brisk Storm: whereupon I sent to make inquiry at a
place call'd _Brill_, which standing upon a much higher ground, I supposed
might be more obnoxious to the effects of the _Earth-quake_ (of which, had
I had any suspition of it, my having formerly been in one neer the _Lacus
Lemanus_, would have made me the more observant:) But the person I sent to,
being {181} disabled by sickness to come over to me (which he promis'd to
do, as soon as he could) writ me only a _Ticket_, whose substance was, That
the _Earth-quake_ was there much more considerable, than where I lodged,
and that at a Gentlemans house, whom he names (the most noted Person, it
seems, of the neighbourhood) the House trembled very much, so as to make
the Stones manifestly to move to and fro in the Parlour, to the great
amazement and fright of all the Family. The Hill, whereon this _Brill_
stands, I have observ'd to be very well stor'd with Mineral substances of
several kinds; and from thence I have been inform'd by others, that this
Earth-quake reach'd a good many miles; but I have neither leasure, nor
inclination to entertain you with uncertain reports of the Extent and other
Circumstances, especially since a little further time an inquiry may enable
me to give you a better warranted account.
* * * * *
_Some Observations and Directions about the _Barometer_, communicated by
the same Hand, to the _Author_ of this _Tract_._