'#5 PHILOSOPHICAL TRANSACTIONS. [aNNO 1750. 



some observations made on substances hastening or promoting putrefaction ; an 

 inquiry not less useful than the former. For, setting aside the oftensive idea 

 commonly annexed to the word, we must acknowledge putrefaction to be one of 

 the instruments of nature, by which many great and curious changes are brought 

 about. With regard to medicine, we know that neither animal nor vegetable 

 substances can become aliment, without undergoing some degree of putrefaction. 

 Many distempers proceed from a deficiency of this action. The crises of fevers 

 seem to depend on it; and perhaps even animal heat, according to a late inge- 

 nious theory.* 



But, in the prosecution of this subject, he had met with very few real septics; 

 and found many substances, commonly accounted such, of a quite opposite na- 

 ture. The most general means of accelerating putrefaction is by heat, moisture, 

 and stagnating air; which being sufficiently known and ascertained, he passed 

 over, without making any particular experiment on those heads. Lord Bacon, 

 (vide Nat. Hist. cent. iv. exper. 330,) as well as some of the chemists, has hinted 

 at a putrid fermentation, analogous to what is found in vegetables; and this hav- 

 ing so near a connection with contagion. Dr. P. made the following experiment, 

 for a further illustration of this matter. 



5. In the yolk of an egg, already putrid, a small thread was dipped, and a 

 small bit of this was cut oft' and put into a phial, with half of the yolk of a new- 

 laid egg diluted with water. The other half, with as much water, was put into 

 another phial, and both being corked, were set by the fire to putrefy. The 

 result was, that the thread infected the fresh yolk, for the putrefaction was 

 sooner perceived in the phial that contained it, than in the other. But this ex- 

 periment was not repeated. 



In this manner the putrefaction of meat advances quicker in a confined than 

 a free air ; for as the most putrid parts are also the most fugitive ; they incessantly 

 issue from a corruptible substance, and disperse with the wind; but in a stagna- 

 tion of air, they remain about the body; and by way of ferment excite it to 

 corruption. 



6. As for other septics, recited by authors. Dr. P. found none of them answer 

 the purpose. The alkaline salts have been considered as the chief putrefiers. 

 But this is disproved by experiments. Of the volatiles it may be indeed observed, 

 that though they preserve from the common marks of putrefaction, with a force 

 4 times greater than that of sea-salt ; yet, in warm infusions, a small quantity of 

 these salts will soften and resolve the fibres, more than water does by itself. 

 They also hinder the coagulation of blood , and when taken by way of medicine, 



♦ An Essay on the Cause of Animal Heat, by J. Stevenson, m. d. Vide Medical Essays, vol. y. 

 — Orig. 



