608 Proceedings of the Royal Society of Edinburgh. [Sess, 
sectionising, with the result that in neither head was there a difference of a 
millimetre. 
The reconstructed head was next placed in a box in a vertical position, 
and one half of the head was completely embedded in plaster of Paris. In 
this way the future immobility of the replaced sections was absolutely 
guaranteed, whilst one lateral half of the head was free for further 
investigation. 
The box containing the reconstructed and partially embedded head was 
next firmly screwed to the board of Martin’s dioptrograph. A sheet of 
paper was pinned down to the drawing-board of the apparatus, and upon 
this was recorded an outline tracing of the head, with its various anatomical 
landmarks, such as the ear, etc., together with the lines of section. Upon 
this same sheet of paper were subsequently recorded the dioptrographic 
tracings of bone and brain, the latter for subsequent investigation. 
The skin was next removed from one half of every section and the 
osseous outline dioptrographically recorded, together with the positions of 
the various suturse cranii. The segments of bone were next similarly 
removed from the surface of every section, the meninges removed, and 
the lateral surfaces of the cerebral hemisphere fully exposed. Its 
various sulci and gyri were then drawn in by means of the dioptrograph, 
and lastly the various sections of cerebral hemisphere were removed 
from every section and the structures in the median plane of the head 
exposed and recorded, including, in conclusion, the medial surface of the 
brain itself. 
Upon a single piece of paper there were thus dioptrographically recorded 
the outline of the head and its surface anatomy, the outline of the skull and 
its various sutures, the lateral surface of the brain with its sulci and gyri, 
the medial surface of the brain, the processes of dura mater, and the larger 
blood-vessels. This procedure necessarily produced an excessively compli- 
cated result, but it ensured absolute accuracy, displayed the relative relations 
of structures on the surface to those at deeper planes ; and as each successive 
tracing was recorded in differently coloured waterproof inks, it was easy to 
obtain subsequent simplified tracings as required. 
All the various sections of the brain were carefully removed, after the 
completion of the dioptrographic tracings, for subsequent examination. 
Prior to the section cutting, a plaster mould of each head was taken, from 
which casts were made, which are now located in the Anatomy Museum of 
the University of Melbourne. 
