s the attack of hemiplegia, is
mentioned in Sect. XX. 8. and is similar to that attending vertigo in
sea-sickness, and at the commencement of some fevers. Black stools
sometimes attend the commencement of hemiplegia, which is probably an
effusion of blood from the biliary duct, where the liver is previously
affected; or some blood may be derived to the intestines by its escaping
from the vena cava into the receptacle of chyle during the distress of the
paralytic attack; and may be conveyed from thence into the intestines by
the retrograde motions of the lacteals; as probably sometimes happens in
diabaetes. See Sect. XXVII. 2. Palsy of one side of the face is mentioned
in Class II. 1. 4. 6. Paralysis of the lacteals, of the liver, and of the
veins, which are described in Sect. XXVIII. XXX. and XXVII. do not belong
to this class, as they are not diseases of voluntary motions.

M. M. The electric sparks and shocks, if used early in the disease, are
frequently of service. A purge of aloes, or calomel. A vomit. Blister.
Saline draughts. Then the bark. Mercurial ointment or sublimate, where the
liver is evidently diseased; or where the gutta rosea has previously
existed. Sudden alarm. Frequent voluntary efforts. Externally ether.
Volatile alcali. Fomentation on the head. Friction. When children, who have
suffered an hemiplegia, begin to use the affected arm, the other hand
should be tied up for half an hour three or four times a day; which obliges
them at their play to use more frequent voluntary efforts with the diseased
limb, and thus sooner to restore the dissevered associations of motion.

Dr. J. Alderson has lately much recommended the leaves of rhus toxicodendon
(sumach), from one gr. to iv. of the dried powder to be taken three or four
times a day. Essay on Rhus Toxic. Johnson, London, 1793. But it is
difficult to know what medicine is of service, as the movements of the
muscles must be learned, as in infancy, by frequent efforts.

11. _Paraplegia._ A palsy of the lower half of the body divided
horizontally. Animals may be conceived to have double bodies, one half in
general resembling so exactly the other, and being supplied with separate
sets of nerves; this gives rise to hemiplegia, or palsy of one half of the
body divided vertically; but the paraplegia, or palsy of the lower parts of
the system, depends on an injury of the spinal marrow, or that part of the
brain which is contained in the vertebrae of the back; by