11 
and in this the object to be operated upon, previously coated with 
gum and dried, was arranged, By using a razor instead of a chisel, 
he was enabled to make very delicate sections, the graduations of the 
screw enabling him to determine their thinness also. 
When the sections were floated in water, the gum dissolved and 
cleared the objects of the surrounding wax. By such a method he 
had made very thin sections of brain, spinal cord, insects, animal 
and vegetable tissues, seeds, leaves, &c., specimens of which, and of 
the retina of the eye of a sheep, were handed round as illustra- 
tions. . 
Mr. Henwan then showed how, with the same kind of instrument, 
sections of wood or the stems of plants could be made by fixing them 
in the gun-metal blocks with paraffine wax before cutting. 
Mr. Wonror illustrated the making of sections of harder sub- 
stances, such as the stones of the peach or the coquilla nut. A thin 
slice was first cut with a fine saw, then ground on a coarse stone, and 
finished off on a water of Ayr stone. 
He then described and performed a process recently devised by 
Dr. Ormerod, for making and mounting sections of bone. A thin 
section of bone was first made with a fine saw ; this was roughly ground 
on a coarse stone, and then finished with a flat piece of pymice stone 
on a plate of ground glass with water. 
After well washing, the superfluous moisture only was removed 
with blotting paper. Canada Balsam was then boiled on the glass slide, 
and algo on the covering glass. When the balsam was nearly cold the 
bone was arranged on the slide, the covering glass put on, and the 
whole being gently warmed, the glass cover was pressed down. By 
this means the structure of bone was admirably shown. A hot knife 
having been run round the edge of the covering glass, the superfluous 
balsam was cleaned off under cold water, the whole process, viz., from 
cutting the slice until the slide was finished and labelled for the 
cabinet, occupied less than half an hour, a very great advantage 
over the ordinary methods to those wishing to study osseous 
structure. 
Thin sections of different objects, made by the different methods 
described, were handed round as illustrations. 
