2 
Sir Everard Home on the 
Every enquiry into the more minute parts of the brain and 
nerves, as well as their ganglions, must be carried on upon 
the field of the microscope, and Mr. Bauer, in consequence 
of the many valuable discoveries which have been made by 
his skilful use of that instrument, has too much zeal for 
science to withdraw himself from such pursuits. 
Considerable advance has been already made in this en- 
quiry by Mr. Bauer's observations on the component parts 
of the blood, the formation of the embryo of the chick, and 
the component parts of the brain. 
These observations are registered in the Philosophical 
Transactions, and the communications have been of so recent 
a date, as not to require that I should do more in this place 
than refer to them. 
In the present Lecture, it is intended to pursue still farther 
the anatomy of the human brain, and to compare it with that 
of fishes, insects and worms ; in the hope that by the esta- 
blishment of such a series of facts, we may throw light on the 
connection between the action of the nerves and the motion 
of the muscles. 
The following circumstances explain the difficulties that 
are met with in the examination of the structure of the hu- 
man brain. 
The transparent elastic matter readily dissolves in water, 
and when in solution the globules become one confused mass. 
The cortical substance containing serum, when it coagulates, 
is different in density from the medullary structure, and rea- 
dily separates from it ; the serum also in drying cracks into 
regular figures, giving it an appearance of a net work which 
is artificial. 
