PATHOLOGICAL ANATOMY, 
43 
§ 244 . 
The morbid contents are found in the bag formed by 
the arachnoid membrane, although not unfrequently also between 
it and the vascular membrane, which is here but loosely connected 
with it,* and also sometimes between the dura mater of the spinal 
marrow and the spinal canal. We are not, however, to con- 
sider all the fluids here collected 'as the product of disease of 
the spinal membranes, as they may descend from the cavity of 
the skull or the c&vities of the brain 1 . When the collection is 
that of water or lymphatic fluid, it is dropsy of the spine, 
Hifdrorhacis 2 . It may be either acute or chronic. It may 
occur alone, or in connexion with dropsy of the head ; and, if in 
high degree, usually produces palsy, by pressure on the spinal 
marrow. Pus is here collected either in ulceration of the spinal 
marrow and its membranes 3 , or from the cavity of the skull 4 , 
from carious vertebrae 5 , as well also as effused from abscesses in 
the neighbourhood 6 . There is also bloody fluid, or pure 
blood, in a fluid or coagulated form, arising both from injuries 
affecting the spine, and from internal causes 7 .” 
The figures have reference to the copious notes that are ap- 
pended, containing references to the authors that have treated on 
these diseases, or cases that are illustrative of them. We will 
take only those that appertain to our own profession. 
[2.] I have found this several times in animals, namely, in monkeys and 
dogs, and especially in tubercular disease, and in sheep with the gid. I have 
also found in a stag, which I kept for many years, and which at last was 
attacked with palsy of the hinder limbs, a considerable quantity of water in 
the spinal canal. 
[6.] In horses and cattle, inflammatory tumours in the neck, and in 
horses ulcers in the pole and in the withers, sometimes effuse pus into the 
spinal canal. 
[7.] This has occurred in a horse from violent exertion, v. Journal de 
Mdd. continue ', Feb. 1811. 
§ 248 . 
Vices of texture of the spinal marrow are generally 
similar to those of the brain. In most instances, inflamma- 
tion of THE spinal marrow, myelitis 1 , which occurs partly 
as a consequence of injuries and diseases of the vertebrae and 
their ligaments, partly as an idiopathic disease, and in greater or 
less connexion with its membranes, gives rise to them. The 
seeming apoplectic effusion of blood in the tissue of the spinal 
marrow itself, frequently arising from congestion of blood and 
from morbid irritation, must be distinguished from this active 
inflammation of the spinal marrow 2 . The diseases in which the 
spinal marrow mostly exhibits the traces of existing irritation 
and inflammation, are many fevers 3 and eruptive diseases 4 , hydro- 
phobia 5 , painters’ colic 6 , epilepsy 7 , trismus 8 , tetanus 9 . St. Vitus’s 
