Edinr 6 Dundas Street
July 16th 1836
My Dear Sir,
I have only this moment received your letter of the 10th July, <1> in consequence of its being addressed to me at Belleville. <2> It would have given me the highest pleasure to have accepted of your kind invitation <3> to Lacock Abbey had it been in my power to attend the meeting of the Association at Bristol; but I am at present endeavouring to make arrangements to go to the continent in consequence of the illness of Lady Brewster <4> to whom a temporary residence in a warmer climate has been recommended, and I have therefore found it impracticable to undertake so long a journey as that which the Association requires this year from its members. The vexation which this had occasioned me before the receipt of your letter has been greatly aggravated by the additional sacrifice which I make in declining your kind hospitality.
I received your account & sketches of the Circular crystals; <5> but being in a state of transition from a secluded to a wandering life I had not time to get the crystals made and examined. The subject is most curious & you should exhaust it before you allow it to go into other hands.
The structure of Tincal or Native Boron, and also of the Borax of the Shops is bi-axal. The last time I saw Sir John Herschel <6> at Slough he shewed me a very curious experiment with Borax which proved ocularly the truth discovered by Fresnel <7> that what is called the ordinary image is formed by the law of extraordinary refraction in bi-axal crystals. The experiment consisted in viewing thro' two inclined faces of the crystals a long line of light, such as the opening between partially closed window shutters.
The crystals which you mention as absorbing polarised light totally, tho' microscopic, are highly interesting. You ought to have accurate d[rawings]<8> made of all the phenomena of coloured crosses formed by the circular crystals, otherwise those who follow you in the inquiry, & who do this, will receive all the credit due to you even tho' they represent nothing more than you have seen.
I am My Dear Sir Ever Most Faithfully yrs
H.F. Talbot Esqr
1. Not located.
3. WHFT invited a number of savants to stay at Lacock Abbey before the meeting of the British Association for the Advancement of Science in 1836. In addition to Brewster, Prof Charles Babbage (1792-1871), mathematician & inventor, Sir Charles Wheatstone (1802-1875), scientist, Dr Peter Mark Roget (1779-1869), scientific writer, Rev William Whewell (1794-1866), Master of Trinity College, Cambridge, Professor and natural philosopher and Sir William Snow Harris (1791-1867), scientist assembled at Lacock Abbey on 16-17 August, leaving at various times for the meeting, which began on 22 August.
4. Juliet, daughter of James Macpherson, MP.
6. Sir John Frederick William Herschel (1792-1871), astronomer & scientist.
7. Augustin Jean Fresnel (1788-1827), physicist, noted for his work on light and on lenses.
8. Text torn away under seal.