My dear Mr Tyndall,
As you are occupied with the interesting subject of Glaciers, I may mention to you some observations of mine connected with the subject
1. Altho’ Prof. Forbes (Travels p. 29)1 mentions that I and Col. Sabine and Elie de Beaumont had seen the veined structure of the Glacier ice, yet he appears as the discoverer, and first publisher of the fact. I discovered it on the 10th Sept[em]b[e]r 1814 and described it in my Journal, and in the Article Glaciers in the Edinb[u]r[gh]. Encyclopaedia2*3 published soon afterwards. I copy the description in my Journal thus—
“In many places there is something like a vertical stratification in the Ice masses stretching in the direction of the valley, and the surface of the Ice has an appearance as if intersected by veins.”4
In my Journal I mention the similarity of the veins to those of rocks.
On the subject of the optical structure of Ice to which you have more than once referred, you will find my observations in the Article Ice in the Edinb[u]r[gh]. Encyclopaedia vol. XI p. 637;5 and in reference to the regelation of the water in Ice cavities you will find a remarkable expt., in the Edinb[u]r[gh].Transactions 1826, vol. X. p. 426–7.6
I am persuaded that the existing controversy respecting the Glaciers—the cause of your hexagonal flowers and liquid hexagon, and the molecular condition of Ice after pressure, cannot be settled till the optical state of the Ice as shown by polarised light has been thoroughly examined.
I am confident that you will never produce either hexagonal Flowers or hexagonal spaces in Ice perfectly crystallised, that is in Ice in which the optical structure is throughout uniaxial, or rather in which the optical axes parallel in every point of the Mass.
I consider the flowers are as the result of the decomposition of a mass in which the molecules have been prevented from taking their proper position, and I have discovered similar phenomena in the decomposition of solid bodies.
I have just received your note of Saturday,7 and I am,
My dear Mr Tyndall, | Ever most truly yours | St. Leonard's College | D. Brewster
St. Andrews | June 7th 1859.
RI MS JT/1/B/129
RI MS JT/1/TYP/1/160
Altho’ Prof. Forbes (Travels p. 29): refers to Forbes’s book Travels through the Alps of Savoy from 1843.
the Article Glaciers in the Edinb[u]r[gh].Transactions: D. Brewster, ‘Glaciers’, Edinburgh Encyclopaedia, 10 (1830), pp. 284–287. In the review [Anon.], ‘Forbes’s Travels through the Alps of Savoy’, Edinburgh Review, 80 (1844), pp. 135–163, it was noted that ‘The earliest observation of this structure was made on the Glacier de Bois, by Sir David Brewster in 1814, as stated by Professor Forbes; and was published in 1816 or 1817 in the article Glacier in the 'Edinburgh Encyclopedia’ (p. 141).
*: Brewster added a marginal note, *Vol. X p. 285.
“In many places … an appearance as if intersected by veins.”: see Brewster, ‘Glaciers’, Edinburgh Encyclopaedia, 10 (1830), p. 285.
the Article Ice in the Edinb[u]r[gh].. Encyclopaedia vol. XI p. 637: D. Brewster, ‘Ice’, Edinburgh Encyclopaedia, 11 (1830), pp. 636–42.
the Edinb[u]r[gh].Transactions 1826, vol. X. p. 426–7: refers to D. Brewster, ‘On the Refractive Power of the Two New Fluids in Minerals, with Additional Observations on the Nature and Properties of these Substances’, Transactions of the Royal Society of Edinburgh, 10 (1826), pp. 407–27.
your note of Saturday: note missing.
Please cite as “Tyndall1621,” in Ɛpsilon: The John Tyndall Collection accessed on