Antique Victorian intaglio tassie seal 'that strain again'

Era: Victorian 1837-1901
Materials: deep green paste 
Size: 17.2x14.1mm and 9.8mm deep
Weight: 6.7g
 
A cleanly reverse carved seal with an image of an ass/donkey braying and the words 'that strain again'. In my mind that strain again is an early reference to a saying we have in the UK, to talk the hind legs off a donkey, which is a tongue in cheek way of saying someone talks too much...
In reference to sealing a letter, it would make sense to use it on long rambling musings!
 This listing is for the loose intaglio. If you wish to have this seal wrapped in gold and set as a pendant please reach out to discuss conversion cost and I will be happy to help you