[ Jean Hyacinthe de Magellan, natural philosopher. ] Autograph Letter Signed ('Magellan'), in English, to the Earl of Buchan, on topics including Adair Crawford's 'new theory of heat in general'.

3pp., 4to. Addressed, with black wax seal, on reverse of second leaf to 'The Earl of Buchan at Kerkhill | by Edinburgh'. In fair condition, lightly aged. He is 'hardly relieved' from 'a very distressing ophthalmy withh great head-ackes [sic]', but thanks the Earl for 'sending the pamphlet of Dr. Homes on the Croup, for my friend Monsr. Le Roy, one of ye. Members of ye. Royal Acady. at Paris'. He is sending him the Philosophical Transactions, 'as regularly as they come out, by the indicated way of Mr. Donalson'. The 'Medal of ye late Captn. Cook [...] has not yet been distributed to ye. members', and will be forwarded by Donalson when it is. 'I can not pretend to be better acquainted with ye. literary news, than I can collect by the Letter of yr Lordship. The new theory of heat in general, as amplified, or expanded to a variety of phenomena, as Dr. Crawford has done, seems to be one of ye. most advancing steps towards imrpoving Science'. He has 'given an extract of this

in french, to the Public, with some little change in the theory'.