PUT
•makes a ftrong effervefcence with acids. Whereas mod other animal humours putrefied, though of a more intolerable feltor, yet contain lefs volatile fait, left extricable, and then not effervefcing with acids. But, what makes the difference be- tween ftale urine, and other putrid fubftanccs ftill more fpe- cific, is its inoft'enfivenefs with regard to health ; whilfl the fleams of moft other corrupted bodies are often the caufe of putrid and malignant difeafes. So far then from dreading the volatile alkali as the deleterious part of corrupted bodies, it fliould rather feem to be a corrector of Putrefaakn. Pringle obferv. on the dif. of the army.
But ftill there remains a prejudice, as if thefe falts being the produce of corruption, fhould therefore haften PutrefaHion ; and that not only in diftempers where they are unwarily taken, but alfo in experiments out of the body. As to the ettefls arifing from the internal ufe of them, little can be faid, un- lefs the kind of difeafe were precifely ftated : for fuppofing thefe falts were by their nature difpofed to promote Putre- faakn; yet if that is already begun, from a languor of circu- lation, and obftruaion, then may the volatiles, by their ftimu- lating and apperient qualities, be the means of flopping its progrefs ; and, on the other hand, though they were really antifeptic, yet, if the humours are difpofed to corrupt, from excefs of heat or motion, thefe very falts by adding to the caufe, may augment the difeafe. So that upon the whole, it feems to be the faireft criterion of the true nature of thefe volatiles, to enquire whether they accelerate or retard Putre- faakn out of the body.
In order to decide this queftion, repeated experiments were made, by joining both the fpirit and the fait of hartfhorn to various animal fubftanccs; and it was conftantly found, that fo far from promoting Putrefaakn, they evidently hindered it, even more powerfully than common fea-fak. Hence, the Do3or thinks it probable, that the fame taken by way of medicine, will likewife prove antifeptic ; or at leaft, that we cannot juftly fuppofe them corrupters of the humours, more than fermented fpirits or fea-falt. With regard to the Putrefaakn of dead bodies, it is found that fome parts corrupt much fooner than others. Thus, as the abdominal vifcera and mufcles corrupt the fooneft, it is a rule with anatomifts, to begin their diffections and demon- ftrations with thofe parts, the quick PutrefaSlion of which may be afcribed to the putrid fleams of the faxes. Next to the abdominal vifcera and adjacent parts, the lungs are commonly fooneft tainted ; either from the air ftagnating in the veficula: broncbialcs, or from fome remains of perfpirable matter, that by aflillg as a ferment, may haften the Putrefaakn. Id. ibid. p. 392.
It is obfervable, that the Putrefaction of meat, and other fubftances, advances quicker in a confined than free air ; for, as the moft putrid parts are alfo the moft fugitive, they inceffantly illlie from a corruptible fubftance, and difperfe
P Y T
with the wind ; but, in a {lagnation of air, they remain a-
bout the body j and, in the nature of a ferment, excite its
corruption.
PutrefaSlion is one caufe of bilious and intermitting fevers, the
dyfentery, malignant or peftilential fevers, the fcurvy, lepra
Arabum, &c. See the articles Bilious, Dysentery,
Malignant, &c. Append.
Thofe fubftances which refift Putrefaclion, are called Ami-.
fepticSy and the promoters of it Septics. See the articles
Antiseptics and Septics, Append.
PutrefaSlion of the blood. See the article Blood, Append.
PUT RID ferment. See the article Ferment, Suppl.
Putrid fever. See the articles Bilious and Malig- nant.
PUTREFIERS, among phyficians, the fame with Septics. See the article Septics, Append.
PYE, or Magpye, in ornithology. See the article Pica, Suppl.
&7<z-Pye, in ichthyology, the EngKfh name of the Pica mari- na. See the article Pica marina.
PYROMETER, the name of a machine contiived to meafure the alteration of the dimenfions of metals, arifing from heat.
Mufchenbroek, who was the original inventor of this ma- chine, has givena table of the expanfion of the different metals, in the fame degree of heat. See the article Heat, Append. As to the conitruftion of the Pyrometer, the curious may con- fult Defagul. Experim. Philofoph. p. 42 1> feq. But it has been obferved, that Mr. Mufchenbroek's Pyro- • meter was liable to fome objections, and thefe have been re- moved, in a good meafure, by Mr. Ellicott, who has given a defcription of his improved Pyrometer in the Pbiiofophical . Tranfaflions, N° 443. This may alfo be feen in Dr. Mar- tyn's Abridgment, vol. 8. p, 4.64.
In this Pyrometer the 'lengthening of a bar of metal by heat xq of an inch, will carry an index once round a circle di- vided into 360 degrees, fo that if the metal lengthens the 7200th part of an inch, the index will move one degree, ibid. By the help of this inftrument Mr. Ellicott found, upon a medium, that the expanfions of bars of different metals, as nearly of the fame dimenfions as poifible, by the fame degree of heat, were as follows :
Gold,
Silver,
Brafs,
Copper,
Iron,
Steel,
Lead,
73
103
95
89
60
56
149
The great difference between the expanfions of iron and brafs, has been applied with good fuccefs to remedy the irre- gularities in pendulums arifing from heat. Phil. Tranf. Vol. 47. p.485. SeethearticiesHEATandP£NDlJi.uM,4>jS«K/. PYTHAGORIC, or Abacus table. See the article Table, Cycl,
Q^
