An iron cement which resists heat and moisture:—
| Clay | 10 |
| Iron filings | 5 |
| Vinegar | 2 |
| Water | 3 |
A very strong waterproof cement for iron:—
| Iron filings | 100 |
| Sal-ammoniac | 2 |
| Water | 10 |
This in a few days will begin to turn into a hard rust.
Another OXIDISED CEMENT, which holds like iron, is made as follows:—
| Iron filings | 65 | |
| Sal-ammoniac | 2 | .5 |
| Flowers of Sulphur | 1 | .5 |
| Sulphuric acid | 1 |
The sulphuric acid is diluted with water and added to the mixed powders.
A rust or oxide cement, resisting fire:—
| Common iron filings | 45 |
| Clay | 20 |
| Finest porcelain clay | 15 |
| Salt in water | 8 |