400 
DISEASES OF THE AIR-PASSAGES OF HORSES. 
circumstances. As debility advances, whether of the mucous 
membranes or of the frame in general, their vital cohesion is less¬ 
ened ; their vessels are deprived of the requisite support; and 
softening, asthenic ulceration, and hsemorrhage from their surface, 
are the consequences. 
In many cases of acute glanders which came under my obser¬ 
vation in 1826 and 1827, a period remarkable for the prevalence 
of glanders and the destruction of a vast number of horses by it, 
such were the early manifestations of inflammatory action in the 
respiratory muco-bronchial surfaces, that acute glanders was appa¬ 
rently produced by or commenced with bronchitis. On dissection 
the bronchial membrane presented softening, ulceration, and gan¬ 
grenous sloughs. 
Strangles is frequently complicated with bronchitis in its as¬ 
thenic form. When the vital energies of the frame are adequate 
to the full performance of all the functions of the associated organs, 
the former disease runs its course comparatively mildly, and termi¬ 
nates favourably; but, when the above functions are depressed by 
causes which lower the vital actions in a general and severe man¬ 
ner, the disease presents a varied and different train of pheno¬ 
mena, and consecutive lesions are developed in different and dis¬ 
tant situations from the original seat of action. 
In asthenic disease, the primary inflammation of the membran¬ 
ous surface, or of the cellular tissue is disposed to extend in every 
direction, without any interval of space; but it may advance to 
remote parts, and the interval of space present no manifest altera¬ 
tion. This is illustrated by several forms of inflammation of the 
cellular tissue, and of the serous and mucous membranes. When 
the powers of resistance are weak, and the extension of the dis¬ 
ease is continuous, the fluids effused from the parts primarily in¬ 
flamed have acted as irritants to the healthy structures with which 
they have come in contact; and the greater number of the' com¬ 
plications presented during febrile diseases are produced either by 
the state of the fluids secreted, or the morbid condition of the 
blood, the vascular system being excited by their impressions to 
increased action, wanting both of power and healthy tone. At the 
same time the organic influence is very susceptible of the impres¬ 
sions made by the morbid blood and altered fluids, and becomes 
extremely depressed, rendering the tissues that come into contact 
with the diseased secretions unable to resist by their own healthy 
secretions their morbid impressions, this diseased influence being 
soon succeeded by athenic inflammation. 
Ejnzootic Catarrhal Fever, or Influenza .—This latter term has 
become of general use to express the existence of this form of fever, 
under the impression that it is the product of a peculiar or specific 
