| Purified brick-dust | 10 |
| Calcined lime | 10 |
| Purified red iron ore | 10 |
Work this to a paste with dissolved soda. Modifications of this combination of soda with iron and brick-dust will readily occur to all who have carefully studied this work.
A cement for wood:—
| Slacked lime powder | 1 |
| Rye-meal | 2 |
| Linseed-oil varnish | 1 |
To which burnt umber or similar powder may be added at discretion. This cement dries slowly, but becomes very hard. It is good for filling cracks, holes, &c.
French glue for wood:—
| Gum-arabic | 1 |
| Water | 2 |
| Potato starch | 3-5 |
Sawdust, as I have explained, from my own conjecture and experiment, can be combined with cements so as to form an artificial wood, which can be easily moulded or carved, and with which all kinds of worm-eaten and decayed wood can be restored. I find that for this purpose Lehner gives the following:—
“Take the finest sawdust and combine it with linseed-oil varnish, kneading the mass very carefully.”
This, when properly combined and worked, would form a very good artificial wood. It may be here observed, that because the experimenter finds at a first trial that the wood is too brittle or too hard, he is not to conclude that the recipe is good for nothing. Thus, to prepare it with, glue we should take—