It is remarkable that nocturnal radiation as registered at sunrise is much more powerful at Mirzapore than on the more exposed Kymore plateau; the depression of the thermometer freely exposed being 3° greater, that laid on bare earth 6°, and that on the grass 1·4° greater, on the banks of the Ganges.
During my passage down the Ganges the rise of the dew-point was very steady, the maximum occurring at the lowest point on the river, Bhaugulpore, which, as compared with Mirzapore, showed an increase of 8° in temperature, and of 30·6° in the rise of the dew-point. The saturation-point at Mirzakore was ·331, and at the corresponding hours at Bhaugulpore ·742.
MIRZAPORE (Mean elev. 362 feet)
| March 9th to 13th, 1848 | ||||
| Hour | Sunrise | 9 a.m. | 3 p.m. | 9 p.m. |
| TEMPERATURE Mean Max. Min. Range | 61·1 63·0 58·0 5·0 | 76·1 83·0 71·0 12·0 | 86·0 -- -- -- | 76·0 -- -- -- |
| WET-BULB Mean Max. Depression Min. Depression | 48·8 51·5 47·0 | 58·5 56·5 51·7 | 61·7 24·3 -- | 63·5 12·5 -- |
| Elasticity of Vapour | ·236 | ·302 | ·295 | ·480 |
| DEW-POINT Mean Max. Min. Max. Depression Min. Depression | 34·3 39·7 29·7 32·8 23·8 | 41·9 -- -- 52·3 15·7 | 41·3 -- -- 44·7 -- | 55·2 -- -- 20·8 -- |
| Weight of Vapour in cubic feet | 2·574 | 3·271 | 3·089 | 5·127 |
| SATURATION Mean Max. Min. | ·405 ·450 ·327 | ·324 ·603 ·176 | ·264 -- -- | ·511 -- -- |
| Number of observations | 3 | 3 | 1 | 1 |
| Air in shade Sunrise | Exposed Therm. | Diff. | Exposed on earth | Diff. | Exposed on grass | Diff. |
| 60·0 62·5 63·0 58·0 | 55·0 54·5 55·5 53·0 | 5·0 8·0 7·5 5·0 | -- 56·0 50·5 54·0 | -- 6·5 12·5 4·0 | 52·0 52·5 50·5 50·0 | 8·0 10·0 12·5 8·0 |
| 60·9 | 54·6 | 6·4 | 53·5 | 7·7 | 51·3 | 9·6 |
B.
ON THE MINERAL CONSTITUENTS AND ALGÆ OF THE HOT-SPRINGS OF BEHAR, THE HIMALAYA, AND OTHER PARTS OF INDIA, ETC., INCLUDING NOTES ON THE FUNGI OF THE HIMALAYA.
(By Dr. R. D. Thomson and the Rev. M. J. Berkeley, M.A., F.L.S.)
The following remarks, for which I am indebted to the kindness of the able chemist and naturalist mentioned above, will be highly valued, both by those who are interested in the many curious physiological questions involved in the association of the most obscure forms of vegetable life with the remarkable phenomena of mineral springs; or in the exquisitely beautiful microscopic structure of the lower Algæ, which has thrown so much light upon a branch of natural history, whose domain, like that of astronomy, lies to a great extent beyond the reach of the unassisted eye.—J.D.H.
1. Mineral water, Soorujkoond, Behar (vol. i., [p. 27]), contains chloride of sodium and sulphate of soda.
2. Mineral water, hot springs, Yeumtong, altitude 11,730 feet (see vol. ii., [p. 117]). Disengages sulphuretted hydrogen when fresh.—This water was inodorous when the bottle was opened. The saline matter in solution was considerably less than in the Soorujkoond water, but like that consisted of chloride of sodium and sulphate of soda. Its alkaline character suggests the probability of its containing carbonate of soda, but none was detected. The rocks decomposed by the waters of the spring consist of granite impregnated with sulphate of alumina. It appears that in this case the sulphurous waters of Yeumtong became impregnated in the air with sulphuric acid, which decomposed the felspar,[[397]] and united with its alumina. I found traces only of potash in the salt.