VETERINARY SCHOOL AT ALFORT. 151 
become re-animated as soon as the pulmonary circulation becomes 
re-established. 
16. External revulsives constitute powerful assistants in the 
treatment of every stage of pneumonia. In the commencement, 
mustard poultices recommend themselves, especially by the 
promptness and intensity of their action, which is proportionate to 
the rapidity of the progress and to the intensity of the disease, 
and therefore counterbalances its effects. The best place to apply 
the poultice is upon the sub-thoracic region and the inner surface of 
the fore limbs. 
17. Setons, which are slower in their effects, and more cir- 
cumscribed in their sphere of action, are especially suitable after 
the disease is established, their efficacy arising less from the san- 
guineous revulsion they determine than from the secretion induced 
by them. By depriving the blood of a considerable portion of 
its active principles they beneficially counteract the plastic pheno- 
mena, and the anormal secretions likely to arise therefrom within 
the pulmonary tissue. 
The best place for the application of a seton is the costal region, 
parallel with the direction of the sides. 
18. The application of setons to the sides is occasionally followed 
by hot and painful swellings, which take on a gangrenous character 
and cause death. This complication, so much to be feared, is fre- 
quently induced by the state of body of the patient. Where the con- 
stitution is seriously exhausted and weakened anteriorly to the deve- 
lopment of the disease, — or even where the pernicious influence of 
this latter has too long exercised an oppressive action upon the vital 
powers, and too long opposed their sanatory re-action, — the tissues, 
irritated by the tape of the seton, may not undergo the requisite in- 
flammatory modifications to protect them from contact with external 
bodies. Putrefaction in consequence takes place; gangrene follows, 
rapid in its progress and fearful in its effects ; consecutive of which 
is the almost certainty of the system becoming affected by the septic 
matter, and then death ensues. 
19. Howbeit, the causation of gangrene is not always so 
fatal. In many cases it may be attributed to some part of the 
performance of the operation itself. Thus, it not unfrequently 
happens that the gangrene consecutive on the application of a 
seton to the side arises from a laceration of the intercostal muscles 
by the point of the instrument, or is caused by the needle having 
taken a wrong course through the cellular tissue or the subcuta- 
neous muscles. *In these cases the animal matters, viz., the blood, 
the serosity, and the ill-conditioned pus, may become collected in 
bags or cavities, undergo alteration from contact with the air, and 
