Laudator Temporis Acti

Samuel Johnson, London 134-143:

Well may they venture on the Mimic's art,
Who play from Morn to Night a borrow'd Part;
Practis'd their Master's Notions to embrace,
Repeat his Maxims, and reflect his Face;
With ev'ry wild Absurdity comply,
And view each Object with another's Eye;
To shake with Laughter ere the Jest they hear,
To pour at Will the counterfeited Tear;
And as their Patron hints the Cold or Heat,
To shake in Dog-days, in December sweat.

This is an imitation of Juvenal 3.100-103 (tr. G.G. Ramsay):

They are a nation of play-actors. If you smile, your Greek will split his sides with laughter; if he sees his friend drop a tear, he weeps, though without grieving; if you call for a bit of fire in winter-time, he puts on his cloak; if you say 'I am hot,' he breaks into a sweat.

natio comoeda est. rides, maiore cachinno
concutitur; flet, si lacrimas conspexit amici,
nec dolet; igniculum brumae si tempore poscas,
accipit endromidem; si dixeris "aestuo," sudat.

I'm sure someone else besides me has noticed the parallel in a poem by Ammianus, Greek Anthology 9.573 (tr. W.R. Paton):

Sit not, O man, at another's table indulging thy belly with the bread of reproach, now weeping with the weeper and the sour-countenanced, and now laughing with the laugher, sharing both laughter and tears when thou hast no need of either.

Μὴ σύ γ' ἐπ' ἀλλοτρίης, ὤνθρωφ', ἵζοιο τραπέζης
    ψωμὸν ὀνείδειον γαστρὶ χαριζόμενος,
ἄλλοτε μὲν κλαίοντι καὶ ἐστυγνωμένῳ ὄμμα
    συγκλαίων καὖθις σὺν γελόωντι γελῶν,
οὔτε σύ γε κλαυθμοῦ κεχρημένος, οὔτε γέλωτος
    καὶ κλαιωμιλίη, καὶ γελοωμιλίη.

Ammianus seems to have been roughly contemporary with Juvenal. Another poem by Ammianus (Greek Anthology 11.226) recalls the last couplet of an epigram by Juvenal's friend Martial (9.29). Here they are for comparison.

Ammianus, Greek Anthology 11.226 (tr. W.R. Paton):

May the dust lie light on thee when under earth, wretched Nearchus, so that the dogs may easily drag thee out.

Εἴη σοι κατὰ γῆς κούφη κόνις, οἰκτρὲ Νέαρχε,
    ὄφρα σε ῥηιδίως ἐξερύσωσι κύνες.

Martial 9.29.11-12 (tr. D.R. Shackleton Bailey):

Let earth be light upon you and soft sand be your covering, lest the dogs be unable to dig up your bones.

Sit tibi terra levis mollique tegaris harena,
    ne tua non possint eruere ossa canes.