| RefNo | MS/603/1/198 |
| Level | Item |
| Title | Letter from George J [James] Burch, Norham Hall, Oxford, to [Joseph] Larmor |
| Creator | Burch; George James (1852-1914); British physicist |
| Date | 1 June 1908 |
| Description | He had been going to ask Larmor's advice about their paper before his message came. He has made experiments with silica tubes and has concluded that they had probably seen more than one line, but because they used either a hand-held or old fashioned spectroscope, it was impossble to get reliable readings on different lines. What they saw in some cases was the mercury green line, but this has not been seen in such circumstances before. They exhausted a water pump with a mercury gauge; there was no sign of the mercury until the tube was heated then the green line appeared, but disappeared when the tube cooled. But he observed the line when the mercury gauge was not in use and in tubes that had never been employed for mercury. He discusses this, and sodium lines. He will try to get rid of the mercury with gold leaf. The effect of the sodium on the glass tube is very curious. If the tube is washed out with dilute nitric acid after sparking, a strong reaction of iron can be seen, but he could not detect mercury even if the green line had been bright. In Watts index of spectra there is an iron line almost identical to the mercury one, but faint. He is now trying to identify this third green line that occurs when neither mercury of sodium are present. On some occasions they must have simply seen mercury, but perhaps that in itself is novel. They have a clue as to the readiness with which this happens but they will write later on that. If Larmor thinks the facts as stated justify a preliminary publication note, Burch would agree to it being done, but if Larmor thinks it better to wait for additional experiments, he will. This letter is not for publication, of course. |
| Extent | 8p. |
| Format | Manuscript |
| PhysicalDescription | Ink on paper |
| AccessStatus | Open |
Fellows associated with this archive
| Code | PersonName | Dates |
| NA1360 | Burch; George James (1852 - 1914); professor of physics | 1852 - 1914 |