thefe or other Caufes jointly contribute, I cannot tell. But 'tis plain when the Steam in the Stomach, or any Part of the Guts becomes ftronger than the Preffure of the Air, it will repell the Blood out of the Blood-veffels in the Sides of that Part, extend the Sides of that Part, and straighten or flatten the Blood-veffels therein. Whether the Glands in the Valves or Stops in the Guts be opened by Steam, which always has Paffage from top to stop, unless accidentally ftopped, or by Juices fecreted the laft out of the Glands in the Sides of the Part above, which in a Vomit or Purge feem to be most penetrating, or by fome Juices iffued out of peculiar Glands near the Valve or Stop, or by the Juices in the Mash when they are fermented or fharpened to fuch a Degree; or whether one of them may be opened by one Means, and another by another, I cannot tell. The Corpufcles of the Steam may open the Glands in a Valve or Stop, where they have free Paffage to it, but if there be thick Excrements above it they will ftop it. If the Juices pafs any confiderable Distance from above, they must operate on all the Parts they pass through, and make the Bags, er Folds, capable of fending down the

Fluid,

Fluid, and there must be a confiderable Quantity of them, if they mix in the Mash, to act at the Bottom: If the Juices iffue near the Valve or Stop, they may come at it unmixed, and without making any Alteration above; though they are all opened by the Corpufcles in fome fort of Diet, and by the Mash when fermented, or sharpened by a great Quantity of Juices. I think ordinarily the Glands in the Valves, especially the low ones upon which the drier Excrements reft, are opened_by Juices iffued out of the Sides of the Guts next above them; however it is, a plentiful Discharge cools and eases all the Body more than could be done barely by dif charging the Excrements, 'tis likely it is by discharging the Juices out of the Glands, Blood, &c. During the Time that there is an extraordinary Ferment in the Contents of the Stomach and Guts by the Qualities of the Meat, Drink, by too great an Emiffion of Juices, or that all the Parts continue too much diftended by the Crafsnefs of the Steam or Stoppages in the Veffels, the Discharges of the Excrements downward cannot be regular; because none of the Bags can be lifted up and emptied; and when the Steam does not rife in due Proportion in any of the lower

1.3

lower Parts, for Defect of the Caufes aforefaid, they will not extend and lift up thofe above them, to discharge the Fluids out of their Bags downward. When too great a Quantity of Juices, or Juices too fharp, are fecreted into the Stomach, or any of the upper Parts, they do not only make too great a Ferment there, but in all the Parts as they pafs, till that Fluid, and all it mixes with, be difcharged. When the Guts are vaftly diftended, and the Stomach contracted, one can fcarce get any Meat or Drink down into the Stomach, and perhaps they fcarce let the Bottom of the Stomach fettle low enough to keep the Fluids till the Meat be digef ted. It will not feem ftrange, why one Part of the Guts contracts, while another extends, or why the Steam in one Part is ftronger than the Steam in another, fince, as I faid, the Strength of fuch infinitely fmall Agents, is to be computed by the Numbers. And 'tis easy to compute how vaft a Difference there must be between the Number of Agents in the Mash, when it is newly put into the Stomach, and the Juices fecreted into it; fome of their Corpufcles being extremely fubtile, and fome of them capable of being vaftly expanded; and in the Remainder of

the

3.

the Mash, when it has undergone the Fermentation, and the Agents and Parts they could bear are moftly gone off in Steam, or between that Remainder of the Math when it's fo left, and when a new fupply of Juices are fecreted into it, and a new Fermentation raifed, or between the Juices iflued for Discharge by the Sides of Excrements, almoft dry, which Juices will be immediately expanded and railed into Steam, and the fmall Quantity of Steam which could be iffued out of thofe dry Excrements. If there were not The Ufes fuch Stops and Bags in the Stomach and of the Stops and Guts, the Stomach could not retain the Bags in Aliment till it had digefted it, the fmall the StoGuts till most of the Fluids were born Guts. off in Steam, the Colon till it had fermented the Remainder a-new, the End-Gut till it had fent off the Humidity, and fe creted Juices to discharge the Excrements. If there were not fuch Valves or Stops, / which when shut ftopped the Steam, no Part could be contracted by an Abatement of the Steam there, because it would be equal in all Parts, nor could the various Operations of each Part be managed alone, if thofe Valves did not divide, and keep them in feveral Parts as they are. When the Steam is spent in one Part, the I 4 Valves

mach and

Valves can fhut, the Juices contract that Part, and discharge for their feveral Ufes, while the Steam iffues from another Part to circulate the Blood. Befides all the Mash would fall to the loweft Parts, and they would be full, and all the upper Parts empty, and the Steam would continually prefs the Excrements upon the Fundament, and when it opened, make too great Discharges both of Excrements and Steam. Indeed human Bodies, and those which go upright, have more occafion for Stops in their Guts, than those Creatures have which go upon all four, with their Bodies parallel to the Ground.

The Secretion of the Juices into and out of the Glands, the raifing, paffing and perfpiring of the Steam out of the Pores, Lungs, &c. and the Discharge of the Excrements being principal Actions in the Body, let us confider what furthers or hinders them.

CHA P.