1886. ] On the Mounting of Fossils, 355 
white sugar four parts, gum arabic eight parts and water q. s., 
boiled together after the manner of an apothecary. Latterly we 
have added a small quantity of salicylic acid to prevent fermenta- 
tion. It should be about as thick as honey, and for joints that 
do not fit neatly it is well to thicken it at the moment of using | 
with plaster of Paris. For filling large voids plaster enough 
should be kneaded in to make a stiff putty, and it is well to work 
in with it as many pieces of stone or brick as possible, both to 
Save material and to lessen the shrinkage of the mass. 
Although I sometimes paint the masses of plaster which show i 
themselves, to destroy the unpleasant violent contrasts of color, I 
always use some neutral tint entirely different from the color of 
the fossil, in order that the false parts can be easily ‘distin- 
guished, 
With the outfit described, a smooth-grained and moderately 
hard matrix and good hard bones the work is pleasant and easy. 
But when the matrix is of cemented gravel, here hard as flint, there 
loose sand, with soft and crumbly bones, a large stock of patience 
and good temper must be laid in also. 
When the bone is freed from the matrix and mended, the ques- 
tion comes up as to how to keep it safely and show it to advan- 
tage. Hf economy of space be important, a drawer just deep 
enough to receive it is perhaps the best receptacle ; but if we wish : 
to exhibit it to the public a glass case is needed. - “ 
To ordinary observers, and even to pretty fair anatomists, bones 
on a tray or shelf say little. In a museum the inexpert visitor 
must, for obvious reasons, be considered as well as the student 
and professor, and experience shows that a bone in its natural ne 
Position, even if alone, is easier to understand than when reversed, 
Wille it séveral bones are combined sò as to form a foot, or leg, — 
4 spinal column or a skull, the value of each is greatly increased. — 
Following out this idea I have been led to mount every skull, or 
limb, or bone, or even fragment of a bone which has character — 
enough to be worth preserving, and have obtained results better _ 
than my hopes, | os 
, A single ramus of a lower jaw lying on its side in a tray shows ee 
but badly, and is liable to be thrust aside and jostled, to the great 
danger of its teeth and coronoid. But hold it in its natural posi- 
ton, and note its length and width. Then have a neat block of 
“ome hard wood, say cherry or black walnut, cut and polished 
