622 LANCASHIRE VETERINARY MEDICAL ASSOCIATION. 
M. Renault formerly made some experiments with a view to prove 
the indispensable necessity of the absence of air in order to the 
organization of the clot in the interior of the vein. These experi- 
ments have been repeated during the last session, and with the same 
results. 
If the ligature of the vessel, which ordinarily falls off between the 
tenth and sixteenth day, detaches itself before the clot becomes 
perfectly adherent above, or if the membranes have been cut by a 
ligature too tightly drawn, or, finally, if with a view to a practical 
experiment an opening has been made in the vessel above the liga- 
ture — in all these conditions, the air establishing itself in contact 
with the blood, the concentric layers of the clot begin to be effaced. 
The clot itself becomes altered : it liquefies, and escapes through the 
opening in the vessel in the form of a deliquum, which diffuses a 
noisome gangrenous colour. 
The canal of the vein being re-established in consequence of the 
termination of the adherence of the clot, haemorrhage immediately 
succeeds, and the result is inevitable. 
If the exterior inflammation is elevated to too acute a type, the in- 
cubation — if we may use the term — of the clot within the vessel can 
no longer proceed. It suppurates, and an abscess, formed by the 
softened fibrine and by the pus that is mingled with it, is developed 
in the very interior of the vein. 
The condition of things, however, which may render this accident 
less serious is that often, above the place where the too intense 
inflammation has determined the suppuration of the clot, its type is 
sufficiently moderate for it to become adhesive. Then the clot 
becomes organized, and no haemorrhage takes place. 
Finally, when the blood, by reason of the bad constitution of the 
animal, is not in a healthy state, the organization of the clot is slow 
in its formation, the ligature falls before the adhesion is perfect, 
contact with the air is established, and all the phenomena described 
take place. 
Let any one compare these phenomena of which the jugular vein 
is the seat, in consequence of a ligature, with those which exhibit 
themselves in the same vessel when thrombus has determined in- 
flammation there, and he will be struck with their perfect identity. 
Thrombus develops itself in a healthy animal, determines by its 
presence a degree of pressure on the jugular, and effects the oblitera- 
tion of it ; a clot forms in the interior of the vessel ; the ex- 
ternal membrane becomes inflamed ; the organization of the clot 
is effected, and the vein is obliterated. This is the process of 
adhesive inflammation. 
At other times, when at the period the clot is undergoing the 
process of organization, should the animal rub his neck, a dilatation 
of the vein is effected at the place where the puncture for bleeding 
was made, and the adhesion of the interior clot is broken. The air 
establishes itself in contact with it, and effects the softening of it ; 
and then consecutive haemorrhages manifest themselves, more abun- 
dant and more fearful in proportion to the largeness of the openin g 
