474 
Sir Everard Home’s Observations 
lb. oz, dr. 
The weight of the whole brain was - - 231 
The weight of the whole brain of a child between 
six and seven years - - - 2120 
The preceding facts explain satisfactorily that the cerebrum is 
made up of thin convolutions of medullary and cortical sub- 
stance surrounding the two lateral ventricles ; which are un- 
folded when the cavities of those ventricles are enlarged, and 
in this unfolded state the functions belonging to this part of 
the organ can be carried on. 
Although the quantity of water may be so much increased 
without material injury to the functions of the brain when the 
skull is not ossified, yet after that period even a few ounces 
in the lateral ventricles has been known to produce so much 
undue pressure, as to bring on head-ache, general uneasiness, 
a sensation as if the head were too large, loss of spirits, con- 
vulsions, loss of memory of recent events, idiotism, insensibi- 
lity, and death.* 
cortical substance, and there the pia mater, and dura mater adhered together. 
There was no remaining brain between the third ventricle and sella turcica. On the 
left side of the left hemisphere the medullary and cortical substance was only half 
an inch thick. The corpora striata, and thalami nervorum opticorum were small 
and tough : the union between the thalami was elongated into a broad flat ligament. 
The two commissures, and iter ad infundibulum had the natural appearance. The 
pituitary gland had become flattened. The fourth ventricle, tuberculum annulare, 
and cerebellum, had nearly the natural appearance. The olfactory nerves were tough 
and small ; the optic nerves had no medullary pulp ; the other nerves going out of 
the skull had undergone no change. 
* One ounce and half of water in the lateral ventricles, at 4f years old, were ac- 
companied by pain in the head, and great general irritability. Five ounces at 7 years 
by insensibility for 14 days before death. Two ounces and one half at 9 years by 
violent head-aches, an unwillingness to be moved, and stupor. Three ounces at 1 1 
years were attended with loss of recollection of recent events. This began at the 
