Page:Cyclopaedia, Chambers - Volume 1.djvu/580

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DIG

and make that the Ferment ferving principally for the Tli- gefiion of the Food.

All thefe Syflcms are now reduced to three principal Ones; Which we flill find explain'd, and defended in the fcvcral Writings on that Subject : The firft holding Digefcien to be pcrform'd by Fermentation ; The fecond by Trituration 3 And the third by Fermentation, and Trituration together.

The firft Opinion was for a long Time the only one. The Retainers hereto hold, that the Food, after it is receiv'd in- to the Stomach, is there impregnated with certain men- ftruous Juices, which being affiited by the natural Heat of the Stomach, raifes a Fermentation in the Foods, which diffolves, attenuates, and converts them into Chyle.

This was the Syftem of the Ancients ; who, tho' they only exprefs themfelves in general Terms, as diffolving, fofrening, fubduing, Concretion, Qualities, (Sc. yet fcem to have had the Notion of what we call Fermentation. Thus Empedocles and Hippocrates teach, that Tligeftion is perform 'd by a Putrefaction of the Foods, after the like manner as the fame Empedocles holds Water to be converted by Putrefaction into Wine. Hippocrates, and Ariflotle ufe the Term Con- cotlion, which we likewife find in Erotian, 'Plutarch, and ASuar'ms, to exprefs the manner of Fruits ripening, the Mull's changing into Wine, and Pali's riling. Hippocrates exprefsly names Effervefcence, and Fermentation, de vetere Medicine., C. 5. and Galen likewife, L. de Confuetudine, C. 2, And in another Place he afferts, that a certain Sero- fity of the Stomach concurs with the Bile and Spirits to ef- fect T)igefiion. To fay nothing of Cicero, who, according to the prevailing Opinion of his Time, attributes Tligeftion to the Heat of the Stomach. Lib. II. de Nat. Deor.

The Juices, or Ferments in the Stomach, to whofe Action Ttigeftion is fuppofed owing, are, the Saliva, Bile, and Pan- creatic Juice. This is fo true, that in certain voracious Ani- mals, which eat, and digeft fall, particularly Wolves, Oflriches, and Porcupines, the Bile difcharges it fclf immediately into the Cavity of the Stomach; And we have obferved aDifpo- lition analogous thereto in a Man that had been a great Eater.

There are only three Marks to know the Fermentation of Dough and Mull by : Firft, In that the Dough rifes, and f wells; and the Muft boils, and rarifies. Secondly, In that the Bread and Wine made by thefe Fermentations, have dif- ferent Tails and Qualities from thofc the Flower and Muft had before. Thirdly, In that the Bread, and Wine, by Di- itillation, yield Principles that differ in thofe refpects from thofe drawn from Flower and Muft. Now, all thefe Cha- racters are found in the Change made in the Food by 232- gefiion.

Againft this Syflem it is objected by Mr. Hecquet, and others, that in every 24 Hours there is prepared a Pound of Saliva, half a Pound of Bile, and at leaft two Ounces of Pancreatic Juice ; to which is to be added that Stomach- Liquor, refembling Saliva ; the whole amounting to about

1 Pounds, or 13824 Grains of Ferment. Now, fay they, it is allowed by the Chymifts, that one Grain of Ferment is fufficient for 803 Grains of Matter to be fermented; confe- quently 2 Pounds of Ferment would fulficc for 1200 Pounds of Food : Whereas a Man ordinarily does not take above 4 Pounds in a Day.

Now, this, fay they, is an Argument, that Fermentation is not the only, or principal Intention of thefe Juices ; fince, if it had, they would have been better proportioned to the Occafion. And, further, it furnifhes an Objection, fince fuch a Quantity of faline, menftruous Humour, having fo little Bufinefs to employ it in fermenting the Food, muft act on the Stomach, corrode and deftroy the fine Mem- brane it is lined withal, and do other Mifchiefs.

But to this it is anfwered, 1. That, according to Mr. Hecquet himfclf, the Faculty of fermenting only be- longs to the Salts, and that, by his own Computation, half a Pound of Bile only contains 30 Grains of Salt ; and a Pound of Saliva, with two Ounces of Pancreatic Juice, and the Stomach-Liquor, contain but 14 Grains more : So that the Ferment of the Stomach produced each Day, only amounts to about 44 Grains, which were fcarce enough for

2 Pounds of Food. But Mr. Hecquet diminifhes the Quan- tity of thefe Salts too much, which Verheyen, and others, make a deal more. To which is to be added the volatile Salt, mix'd with the Phlegm and Spirits. 2. It is not true, that there is always required a Grain, and only a Grain of Leaven for 800 Grains of Matter. Expe- rience contradicts this Rule. In fome Fermentations there is no need of any Leaven at all, and in others a deal lefs. As to the Ferment's acting on the Membranes of the Sto- mach ; 'tis certain, it does act on, and vellicate the fame when there is no Food to employ it ; and this it is, that occafions the Senfation of Hunger. But as faft as they are corroded, they are repair'd again by the Nourifhmcnt proper to them. The Stomach is fometimes gnawed, and incom- moded by the Menjlruum; but ordinarily it is preferv'd by a vifcid Matter, wherewith its inner Coat is lined.

Another Objection againft this Doctrine, is, that the Chyie yields no inflammable Spirit ; which it fliould, were it the Effect of Fermentation : But Monfr. Aflruc anfwers, that all Fermentations don't produce any fuch Spirit : That of Dough, for Inftance, affords none, nor that of rotten Fruits nor of Acids, or pure Alcali's. The inflammable Spirit, in Effect, requires a fine attenuated Sulphur, which is not found in all Fermentations.

The fecond Syftem was invented, or at Ieaft renewed in the prefent Age ; and has been maintain 'd with a deal of Zeal, and Vivacity, as is commonly the Cafe in any Thing that has the Appearance of Novelty. Thofe who efpoufe this Opinion, contend, that 'tis a mere continual Attrition, or Grinding, that breaks, attenuates, and reduces the Food, and with the Addition of a proper Fluid, forms it into that whitifti Subftance, call'd Chyle; much as Corn is ground be- tween the Stones of a Mill. Which Opinion teems to be con- firrn'd by fomething obferv'd in Birds : Their Gizzard, or Crop, is compofed of two ftrong, folid, compact Mufcles, which rubbing againft each other, and being aflifted by little angular Stones, or Grains of Sand fwallow'd by the Birds, break and grind the dry Food thofe Animals li ve on : And when the Sand is grown fmooth, rhey caft them off with their other Excrements, and fwallow frelll ones.

This Sentiment is thus explain'd by an able Affertor there- of, Mr. Hecquet, in hisTreatife of jDigefiion. Every thing in the Body is Veffel, confequently, every thing therein is hollow. Every thing therein lives, after its Manner ; con- fequently, every thing is in Motion ; Animal Life being no- thing but Motion ; and confequently all the Velfels are in Mo- tion. Now, the Parts of a Body that arc to move, will move towards thofe Sides, where they find the leaft Refiftance. Bur the Place of the leaf! Refiftance in Tubes is the Cavity ; con- fequently, the Motion of the Parts of Veffels is towards their Axes. The Parts of Veffels that are to move, arc the Parie- tes, or Sides, becaufe flexible, and elaftic ; and this Motion can only be effected by an Approximation of thofe Parts : Confequently, the Motion of the Veffels confifts in an Ap- proximation of their Parietes ; It is, therefore, a Sort of Con- traction, Preflion, or Coarctation : Hence, as all the Parts of the Body are only Veffels, they all undergo a Syltole, Pref- lion, or Contraction. Further, all thefe Veffels contain Juices in their Cavities ; And, therefore, all the Juices, or Liquids in the Body are continually comprefs'd. This Preflion is the Action of an Elaftic Force ; confequently the Preflion will be fuch as is the Force ; and, therefore, alternative : Con- fequently, it is a Pulfe, or Palpitation ; and therefore the Juices are continually beaten. Now, thefe Juices are ex- ceedingly divifible ; and confequently are continually atte- nuated, and divided : And a Divifion effected by aPuifation, or Beating, is a Trituration ; and confequently, the Juices in the Body are continually triturated, or ground. The rea- fon why the comprefftve Force fliould be alternative, is, that the Membranes, which compofe the Veffels, confift of two Plans, or Series of Fibres ; the one longitudinal, the other cir- cular, cutting the longitudinal at right Angles : The longi- tudinal are tendinous, and Elaftic ; the Circular are mufcu* lar, or motive, like Sphincters, which comprefs. The Circu- lar are over the Longitudinal, and embrace, or gird them round. The former, we have already obferved, are Elaftic ; and their Elafticity oppofes the Compreffion of the latter. From this Oppofition, or Refiftance, arifes a reciprocal Action, and Reaction, which is the alternative grinding Force required.

To fuch as account for Digcflion from a Ferment, thefe Phi- lofophers object, that Ttigeftion is a Diffolution ; that to pre- pare the Matters for this Diffolution, they mull be foften'd - that the proper Effect of acid Ferments, is, to gnaw, or tear the hardeft Matters, and to harden the fofter, to thicken the fluid, fix the fat, and coagulate the milky : Confequently, that an acid Ferment fliould rather impede, than promote 2)igeJl/on. Add, that befide the Force to grind the Juices, and the Vef- fels to comprefs them, there are likewife Liquors to dilute, and temper them, viz. the Saliva, and Stomach-Liquor. And Mineral Matters, which the Stomach-Liquor cannot diffolve, are found to be worn, and polifli'd after having ftay'd fome time in the Stomach. Now polifhing is the Effect of Triture, or grinding, not of corroding. Accordingly we find Pelotoons, or Balls of Hairs, or Threads in the Stomach of Cattcl, very fmooth, and fliining, and far from any Marks of Corrofion.

The Authors of Trituration require three Things for TU- gefiion to proceed: A Liquor, to wet and dilute the Food, which they find in the Saliva, and Stomach-Liquor : A Veffel, which is the Stomach : And a moving Power to grind, which they imagine to have found in the* Mufcles of the Stomach, Diaphragm, and Abdomen. The moving Force in the Mufcles of the Stomach they maintain £0 be equivalent to a Weight of 248235 Pounds ; and the Force of the Stomach alone, to a Weight of 12951 Pounds : A Power more than equal to that of one of the ableft Mill-Hones. See Traite de la 'lligeftion par Monfr. Hecquet,

So-