670 
ingenuity he ascribes the passage of the nervous 
force(under the name of animal spirits) from one 
part to another, to the anatomical relations of 
those , and the direction of the consti- 
tuent fibres, And, indeed, we may find in the 
writings of this great man the germs of many 
a theory which, in our own times, has been 
brought forward with a more plausible aspect, 
disencumbered of the quaint phraseology and 
superabundant metaphor so common in his 
day. I shall quote one remarkable instance 
as very much in point. Speaking of the fourth 
pair of nerves as connected with the corpora 
quadragemina, he says: “ Concerning these 
little nerves it is observed, that when (although) 
many others proceed from the sides or the basis 
of the oblong marrow, these arise from the 
aforesaid Prominences in the bunching forth at 
the top (nates and testes). The reason of which, 
if I be not mistaken, is this,—we have affirmed 
that these prominences do receive and commu- 
nicate to the brain the natural instinct delivered 
from the heart and bowels to the cerebel; and 
on the other side, or back again, do transfer 
towards the Precordia, by the mediation of the 
cerebel, the forces of the passions or affections 
received from the brain; but in either action 
the motion of the eyes is affected with a certain 
manifest sympathy. For if pain, want, or any 
other signal trouble afflicts the viscera or the 
recordia, a dejected and cast-down aspect of 
the eyes will declare the sense of its trouble: 
when on the contrary, in joy, or any pleasant 
affection of the precordia or viscera, the eyes 
are made lively and sparkle again. In hike 
manner the eyes do so clearly show the affec- 
tions of the mind, as sadness, anger, hatred, 
love, and other perturbations, that those who 
are affected, though they should dissemble, 
cannot hide the feeling and intimate concep- 
tions of the mind. Without doubt these so 
happen because the animal spirits tending this 
way and that way in this deviating place be- 
tween the brain and the precordia, do at once 
strike those nerves as the strings of a harp. 
Wherefore, from this kind of conjecture, which 
we have made concerning the use of these 
nerves, we have called them Pathetical, al- 
though indeed other nerves may deserve the 
same name.”* 
Malpighi and Vieussens were well acquainted 
with the fibrous structure of the brain, and 
appear to have had very correct notions as to 
the general direction which they assume, and 
the parts which they serve to connect to each 
other. The former describes the fibres of the 
brain and cerebellum as taking their origin 
from the trough of the spinal marrow contained 
within the cranium (medulla oblongata); “ for 
they ramify from four reflected crura of this 
medulla in all directions, until they end by their 
branched extremities in the cortex.” Vieus- 
sens states that the medullary substance is com- 
posed of innumerable fibrils connected together 
and arranged into various fasciculi, which be- 
come very obvious when it is boiled in oil.t 
* English edition of Willis’s Works, p. 90, fol. 
684 
Lond. 1684. F 
t Malpighi, Exercitatio Epistolica de Cerebro, 
NERVOUS SYSTEM. (Nervous Centres. Tut Encepnaton.) 
The great merit of Reil, Gall and Spurzhei 
and their followers in later years, consists 
their having followed out with great diligs 
the coarser anatomy of those fibres, and de 
mined many important and undeniable ti 
But in the statements of all anatomists, 
avail themselves of no other aid than 
which the naked eye affords, there is much 
must necessarily be uncertain or doubtful 
is there any other mode of removing the: 
certainties but by the successful applic 
microscopical analysis to the whole e 
structure. a 
Of the surface of the encephalon—W 
proceed to examine the various p 
of notice in the superficial anatomy 
encephalon. 2 
The shape of the brain is determine 
of the cerebral hemispheres. A lil 
around the surface of the latter, so as to 4 
them, would describe an oval, the sn 
tremity of which is directed fo ds. 
The superior and lateral surfaces 
encephalon are convex, and have 
ap nce from the visceral layer of 1 
noid being extended over them, adher 
subjacent pia mater. When the m 
have been removed, the convoluted 
of these surfaces, previously seen thror 
becomes very manifest, as will be m 
cularly described by-and-bye. The lor 
and transverse diameters of these sui 
respond to those of the cranial cavit 
he superior surface is divide 
median plone into two equal and 
degree symmetrical portions by a 
passes vertically between them and re 
great falciform process of the du 
front and behind, this fissure complet 
the central lobes. In the latter sit 
grea cerebelli is seen at the b 
it when the hemispheres are sep 
encephalon be in situ; if it have been | 
however, the superior surface of the ee 
forms the floor of the fissure. In @ 
the fissure is interrupted by a horizont 
of white fibres, which is called the e 
losum, the great commissure of the 
hemispheres. 4 
The inferior surface of the encep) 
called commonly the base of the & 
sents many points worthy the 
anatomist. . 
It is not all upon one level: in 
it corresponds with the disposition of 
of the skull. We find, indeed, three: 
each on a different plane, and corresp' 
each of the three fosse of the craniu 
is best observed by examining a vert 
of the head, the brain being reta 
situation, or by removing the wall | 
nium on one side quite down to i 
surface. nd 
The anterior segment, and hat 
4 
1664. Vieussens, Neurographia Univer 
cap. x. See the whole passages quot 
Gordon’s Observations on the Structure 0 
Edin, 1817, p. 21. = 
