276 LORD LISTER 



inflammatory suppuration, such as that in which ordinary 

 abscesses originate where the pus appears to be formed in 

 consequence of an excited action of the nerves, inde- 

 pendently of any other stimulus. There is, however, this 

 enormous difference between the effects of carbolic acid 

 and those of decomposition; viz., that carbolic acid stimu- 

 lates only the surface to which it is at first applied, and 

 every drop of discharge that forms weakens the stimulant 

 by diluting it; but decomposition is a self-propagating and 

 self-aggravating poison, and, if it occur at the surface of a 

 severely injured limb, it will spread into all its recesses so 

 far as any extravasated blood or shreds of dead tissue may 

 extend, and lying in those recesses, it will become from 

 hour to hour more acrid, till it requires the energy of a 

 caustic sufficient to destroy the vitality of any tissues 

 naturally weak from inferior vascular supply, or weakened 

 by the injury they sustained in the accident. 



Hence it is easy to understand how, when a wound is 

 very large, the crust beneath the rag may prove here and 

 there insufficient to protect the raw surface from the stimu- 

 lating influence of the carbolic acid in the putty; and the 

 result will be first the conversion of the tissues so acted on 

 into granulations, and subsequently the formation of more 

 or less pus. This, however, will be merely superficial, and 

 will not interfere with the absorption and organisation ofc 

 extravasated blood or dead tissues in the interior. But, on 

 the other hand, should decomposition set in before the in- 

 ternal parts have become securely consolidated, the most 

 disastrous results may ensue. 



I left behind me in Glasgow a boy, thirteen years of age, 

 who, between three and four weeks previously, met with a 

 most severe injury to the left arm, which he got entangled in 

 a machine at a fair. There was a wound six inches long and 

 three inches broad, and the skin was very extensively under- 

 mined beyond its limits, while the soft parts were generally 

 so much lacerated that a pair of dressing forceps introduced 

 at the wound and pushed directly inwards appeared beneath 

 the skin at the opposite aspect of the limb. From this wound 

 several tags of muscle were hanging, and among them was 

 one consisting of about three inches of the triceps in almost 





