Many are also of opinion, and some learned Men maintain, that Men are lighter after meals then before, and that by a supply and addition of spirits obscuring the gross ponderosity of the aliment ingested; but the contrary hereof we have found in the trial of sundry persons in different sex and ages. And we conceive Men may mistake if they distinguish not the sense of levity unto themselves, and in regard of the scale or decision of trutination. For after a draught of wine, a Man may seem lighter in himself from sudden refection, although he be heavier in the balance, from a corporal and ponderous addition; but a Man in the morning is lighter in the scale, because in sleep some pounds have perspired; and is also lighter unto himself, because he is refected.
And to speak strictly, a Man that holds his breath is weightier while his lungs are full, then upon expiration. For a bladder blown is weightier then one empty, and if it contain a quart, expressed and emptied it will abate about a quarter of a grain. And therefore we somewhat mistrust the experiment of a pumice stone taken up by Montanus, in his Comment upon Avicenna, where declaring how the rarity of parts, and numerosity of pores, occasioneth a lightness in bodies, he affirms that a pumice-stone powdered, is lighter then one entire; which is an experiment beyond our satisfaction; for beside that abatement can hardly be avoided in the Trituration; if a bladder of good capacity will scarce include a grain of air, a pumice of three or four dragms, cannot be presumed to contain the hundred part thereof; which will not be sensible upon the exactest beams we use. Nor is it to be taken strictly which is delivered by the learned Lord Verulam, and referred unto further experiment; That a dissolution of Iron in aqua fortis, will bear as good weight as their bodies did before, notwithstanding a great deal of waste by a thick vapour that issueth during the working; for we cannot find it to hold neither in Iron nor Copper, which is dissolved with less ebullition; and hereof we made trial in Scales of good exactness: wherein if there be a defect, or such as will not turn upon quarter grains, there may be frequent mistakes in experiments of this nature. That also may be considered which is delivered by Hamerus PoppiusBasilica Antimonii., that Antimony calcin’d or reduced to ashes by a burning glass, although it emit a gross and ponderous exhalation, doth rather exceed then abate its former gravity. Nevertheless, strange it is; how very little and almost insensible abatement there will be sometimes in such operations, or rather some encrease, as in the refining of metals, in the test of bone ashes, according to experience: and in a burnt brick, as Monsieur de Clave Des Pierres. affirmeth. Mistake may be made in this way of trial, when the Antimony is not weighed immediately upon the calcination; but permitted the air, it imbibeth the humidity thereof, and so repaireth its gravity.
[CHAPTER VIII]
Of the passage of Meat and Drink.
That there are different passages for Meat and Drink, the Meat or dry aliment descending by the one, the Drink or moistening vehicle by the other, is a popular Tenent in our daies, but was the assertion of learned men of old. For the same was affirmed by Plato, maintained by Eustathius in Macrobius, and is deducible from Eratosthenes, Eupolis and Euripides. Now herein Men contradict experience, not well understanding Anatomy, and the use of parts. For at the Throat there are two cavities or conducting parts; the one the Oesophagus or Gullet, seated next the spine, a part official unto nutrition, and whereby the aliment both wet and dry is conveied unto the stomack; the other (by which tis conceived the Drink doth pass) is the weazon, rough artery, or wind-pipe, a part inservient to voice and respiration; for thereby the air descendeth into the lungs, and is communicated unto the heart. And therefore all Animals that breath or have lungs, have also the weazon; but many have the gullet or feeding channel, which have no lungs or wind-pipe; as fishes which have gils, whereby the heart is refrigerated; for such thereof as have lungs and respiration, are not without the weazon, as Whales and cetaceous Animals.
Again, Beside these parts destin’d to divers offices, there is a peculiar provision for the wind-pipe, that is, a cartilagineous flap upon the opening of the Larinx or Throttle, which hath an open cavity for the admission of the air; but lest thereby either meat or drink should descend, Providence hath placed the Epiglottis, Ligula, or flap like an Ivy leaf, which alwaies closeth when we swallow, or when the meat and drink passeth over it into the gullet. Which part although all have not that breath, as all cetaceous and oviparous Animals, yet is the weazon secured some other way; and therefore in Whales that breath, least the water should get into the lungs, an ejection thereof is contrived by a Fistula or spout at the head. And therefore also though birds have no Epiglottis, yet can they so contract the rim or chink of their Larinx, as to prevent the admission of wet or dry ingested; either whereof getting in, occasioneth a cough, until it be ejected. Why a man cannot drink and breath at once. And this is the reason why a Man cannot drink and breath at the same time; why, if we laugh while we drink, the drink flies out at the nostrils; why, when the water enters the weazon, Men are suddenly drowned; and thus must it be understood, when we readAnacreon the Poet, if the story be taken literally. of one that died by the seed of a Grape, and another by an hair in milk.
Now if any shall still affirm, that some truth there is in the assertion, upon the experiment of Hippocrates, who killing an Hog after a red potion, found the tincture thereof in the Larinx; if any will urge the same from medical practice, because in affections both of Lungs and weazon, Physitians make use of syrupes, and lambitive medicines; we are not averse to acknowledge, that some may distil and insinuate into the wind-pipe, and medicines may creep down, as well as the rheum before them; yet to conclude from hence, that air and water have both one common passage, were to state the question upon the weaker side of the distinction, and from a partial or guttulous irrigation, to conclude a total descension.