Give me leave to add further, that this presumptive argument in favour of the antiquity of windows made of plates of glass receives an additional force from the close relation, which must be allowed to subsist between them, and those composed of the _lapis specularis_. The former must be looked upon as an improvement upon the other, as they answered all the purposes of convenience, and at the same time were more beautiful; and being the manufacture[61] of Italy, might probably be purchased at a less expence. Upon all which accounts it seems reasonable to conclude, that one of these inventions would naturally be introductory to the other: and consequently, that as window-lights of the _lapis specularis_ began to be used within the memory of Seneca, who died[62] under Nero, about _anno Christi_ 68. (_Helvic._), the original of those of glass may have fair pretensions to a place within the period assigned in the foregoing paragraph, _viz._ some years before the destruction[63] of Herculaneum, in whose ruins the plate before us was buried. To conclude: I need not observe to you, that all the evidence here produced to prove the usage of glass-windows to have been coæval with the fragment we are now considering, is of the conjectural kind only: for, I must confess, I have not been able to trace it up by any positive authority higher than about 200 years short of the epocha last mentioned, _viz._ to the latter end of the third century[64], when it is expresly mentioned by Lactantius in these words:--_Manifestius est, mentem esse, quæ per oculos ea, quæ sunt opposita, transpiciat, quasi per fenestras lucente vitro aut speculari lapide obductas._--De opificio Dei, cap. v. I am, SIR, Your most obedient humble Servant, J. Nixon. LXXXI. _An Account of an extraordinary Case of the Efficacy of the Bark in the Delirium of a Fever. By_ Nicˢ. Munckley, _M. D. Physician to_ Guy’s-Hospital, _and F.R.S._ [Read April 6, 1758.] AS the following case contains some circumstances, which are curious in themselves, and which may be of service to be known, I have thought it proper to be laid before the Society.