470 ON THE INFLUENCE OF CUTANEOUS SECRETIONS. 
Anasarca in horses is, in an immense majority of cases, the 
result of sudden refrigeration of the skin covered with sweat. 
Under the astringent and repercussive influence of cold, the capil- 
lary system of the skin all at once shuts up. The blood carried to 
it by an excentric circulation, suddenly repulsed upon the interior, 
becomes concentrated within the capillaries of the cellular tissue, 
whose exhalence in consequence grows all at once extraordi- 
narily active. Hence the mass of serosity which we behold infil- 
trating the meshes of this tissue, and which, obedient to the laws 
of gravity, accumulates on the same level in the most dependent 
parts of the limbs, as well as of the head and trunk. Among the 
phenomena accompanying this, there is one constant in its presence 
even from the beginning of the disease, whose interpretation has 
escaped us prior to these last experiments. We speak of the 
petechial eruption which appears upon the mucous surfaces, under 
the form of either deep red confluent spots, or of large black 
marbled patches ; so diffuse and approximated in some cases, that 
the surface of the membrane presents one uniform black stain. 
These petechise are such constant accompaniments of subcutaneous 
oedema, that they may serve, in cases of doubt, as a key to the 
character and real nature of these swellings. 
And what are these spots themselves, if not the indication or 
exterior exudation of the changed material contained in the blood, 
therein created under the influence of the suppression of the cuta- 
neous exhalations 1 
In diseases in which, from other causes, the blood is altered in 
its composition, do we not witness the same appearance of petechial 
eruption analogous to what we see in anasarca 1 And is it not 
sufficient to cause to appear, almost at pleasure, a like eruption, to 
submit animals to an absolute abstinence for some days 1 Under 
the influence of prolonged combustion , without reparation of the 
combustible elements, the blood grows black, and the particular 
alteration it undergoes is implied in the petechial eruption upon the 
mucous surfaces. 
This alteration of the blood, which is expressed, from the com- 
mencement of the anasarca, by an eruption of peiechice upon the 
mucous surfaces, is evidently of the same nature as that which 
takes place under the influence of the application of plasters upon 
the surface of the skin ; less intense only, as well as less permanent, 
on account of the possible return of the functions of the skin on the 
cessation of the cause which has suppressed them, though in some 
cases deeply rooted, and tenacious enough to entail the cessation 
of vitality, notwithstanding the respiratory function may be exerted 
to its utmost, be it through the forced dilatation of the nostrils or 
through the operation of tracheotomy. 
