Upon a Lady, who finding her Pocket wet, pretended she had broke her Hartshorn Bottle in it.Hartshorn (the aqueous solution of ammonia) was used in smelling salts. Oxford English Dictionary, s.v. shock, n.4: "A dog having long shaggy hair, spec. a poodle."
Ye sons of verse, transmit to fame,
How blest the life of miss is;
When she breaks wind, Shock bears the blame;
And hartshorn, when she pisses.