22 PRACTICE OF PHYSIC. 



and these must be different, according to the nature of the se- 

 veral causes occasioning that tendency, as may be understood 

 from what has been already said of them. After a gangrene 

 has, in some degree, taken place, it can be cured only by the 

 separation of the dead from the living parts. This, in certain 

 circumstances, can be performed by the knife, and always most 

 properly, when it can be so done. 



In other cases, it can be done by exciting a suppuratory in- 

 flammation on the verge of the living part, whereby its cohesion 

 with the dead may be every where broken off, so that the latter 

 may fall off by itself. While this is doing, it is proper to pre- 

 vent the further putrefaction of the part, and its spreading 

 wider. For this purpose, various antiseptic applications have 

 been proposed : but it appears to me, that, while the teguments 

 are entire, these applications can hardly have any effect ; and 

 therefore that the fundamental procedure must be to scarify the 

 part, so as to reach the living substance, and, by the wounds 

 made there, to excite the suppuration required. By the same 

 incisions also, we give access to antiseptics, which may both 

 prevent the progress of the putrefaction in the dead, and excite 

 the inflammation necessary on the verge of the living part. 



CCLXXII. When the gangrene proceeds from a loss of 

 tone ; and when this, communicated to the neighbouring parts, 

 prevents that inflammation which, as I have said, is necessary 

 to the separation of the dead part from the living ; it will be 

 proper to obviate this loss of tone by tonic medicines given in- 

 ternally ; and, for this purpose, the Peruvian bark has been 

 found to be especially effectual. That this medicine operates 

 by a tonic power, I have endeavoured to prove above (CCXIV.J; 

 and, from what is said in CCXV., the limitations to be observed 

 in employing it may also be learned. When the gangrene arises 

 from the violence of inflammation, the bark may not only fail 

 of proving a remedy, but may do harm : and its power as a 

 tonic is especially suited to those cases of gangrene which pro- 

 ceed from an original loss of tone, as in the case of palsy and 

 oedema ; or to those cases of inflammation where a loss of tone 

 takes place, while the original inflammatory symptoms are re- 

 moved. 



CCLXXII I. The other terminations of inflammation either 



