| Powdered flint | 90 |
| Graphite | 10 |
| Sulphur | 100 |
I.
A fluid paste is made by pouring into a porcelain jar 5 kilogrammes of potato-starch with 6 kilogrammes of water and 250 grammes of white nitric acid. Keep the whole in a warm place for forty-eight hours, stirring it frequently, and then boil it till syrupy and transparent. Add a little water, or sufficient to make it fluid enough to be filtered through a closely woven towel.
II.
Dissolve 5 kilogrammes of gum-arabic to 1 of sugar in 5 quarts of water, adding 50 grammes of nitric acid; warm to boiling, and then add No. I. The result is a perfectly fluid adhesive, which will not mould, and dries on paper with a glaze. It is adapted for postage-stamps, marking over impressions, and fine stationery.
Durable Flour-Paste for Stationers.—Take good flour-paste, adding to it while boiling one-tenth part of clear liquid glue, to be well stirred in. Add a few drops of carbolic acid or oil of cloves. Keep it corked in wide-mouthed, large vials.
Dry Cement, or Travellers’ Glue:—
| Glue | 600 | grms. |
| Sugar | 250 | ” |
The glue must be of the best quality, and perfectly melted in water, as usual, and the sugar stirred in. It is then steamed away until it becomes hard when cold. To use, place it in hot water, when it at once liquefies. This is specially used for paper.
Coating to protect trees from insects:—