Copy letter, from Sir John Herschel to Robert Hunt, dated at Collingwood Copy of letter, copied as part of the correspondence project led by Colonel John Herschel FRS following the death of his father. Robert Hunt's experiments are extremely interesting and deserve to be pursued. Comments on experiments made by Michael Faraday and others relating to the formation of crystals in a magnetic field and the effect such crystals have on polarized light. 5 January 1846