cement, but leaves it when the pressure is diminished. The following are certain pressures and temperatures, which, I believe, are not very far from truth; the marked numbers are from experiment.
| Fahr | Atmospheres. | |
| * | -100 | 1.80 |
| * | -92 | 2.28 |
| -90 | 2.33 | |
| * | -83 | 2.90 |
| -80 | 3.12 | |
| * | 77 | 3.37 |
| -70 | 4.02 | |
| * | 67 | 4.26 |
| -60 | 5.08 | |
| * | -53° | 5-33 . |
| -50 | 6.30 | |
| * | -42 | 7.40 |
| -40 | 7.68 | |
| * | -33 | 8.53 |
| -30 | 9.22 | |
| * | -22 | 10.66 |
| -20 | 10.92 | |
| -10 | 12.82 | |
| * | -5 | 13.88 |
| * | 0 | 15.04 |
| 10 | 17.74 | |
| 20 | 21.09 | |
| * | 25 | 20.03 |
| 30 | 25.32 | |
| * | 32 | 20.20 |
| 40 | 80.67 | |
The result formerly obtained[1] was forty atmospheres at the temperature of 50° Fahr.
'Sulphrous Acid.—When liquid, it dissolves bitumen. It becomes a crystalline, transparent, colourless, solid body at -105° Fahr.; when partly frozen the crystals are well formed. The solid sulphurous acid is heavier than the liquid, and sinks freely in it. The following is a Table of pressures in atmospheres of 30 inches mercury, of which the marked results are from many observations, the others are interpolated. They differ considerably from the results obtained by Bunsen [2], but agree with my first and only result.
| Fahr. | Atmospheres. | |
| 0 | 0.725 | |
| 10 | 0.92 | |
| * | 14 | 1.00 |
| * | 19 | 1.12 |
| * | 23 | 1.23 |
| * | 26 | 1.33 |
| 31.5 | 1.50 | |
| * | 32 | 1.53 |
| * | 33 | 1.57 |
| 40° | 1.70 | |
| 46.5 | 2.00 | |
| * | 48 | 2.00 |
| * | 56 | 2.42 |
| 58 | 2.50 | |
| * | 64 | 2.76 |
| 68 | 3.00 | |
| * | 73.5 | 3.28 |
| * | 76.8 | 3.50 |
| 85 | 4.00 | |
| * | 90 | 4.35 |
| 93 | 4.50 | |
| 98 | 5.00 | |
| * | 100 | 5.10 |
| 104 | 5.50 | |
| 110 | 6.00 | |
Sulphuretted Hydrogen.—This substance solidifies at 122°
