"Shake Well Before Using"
Context: George Colman, Senior, was manager of the Haymarket Theatre when his son was born. Colman the Younger, brought up in the theatrical world, escaped a career in law by writing plays. Turk or No Turk (1785) was followed by musical comedies. Then came a volume of humorous poetry, and his My Nightgown and Slippers (1797) was quickly sold out. A second edition, enlarged, appeared in 1802. One of its tales in verse concerns "The Newcastle Apothecary" Benjamin Bolus, who both brought children into the world as a midwife and ushered them out with his pills. Esteeming himself a literary man, the druggist wrote poetic directions for his medicine. The six stanzas of the poem tell how, taken too literally, the prescription accompanying one bottle caused the death of the invalid because, as the druggist is finally told, the servants administered one dose, then shook their master. When that treatment did not cure him, they repeated the dosage, then "A third we tried."/ "Well, and what then?" "Then, sir, my master died." The modern version of the phrase is, of course, "Shake well before using." At the beginning of the poem, Colman sets the stage.
He had a patient lying at death's door,Some three miles from the town–it might be four;To whom, one evening, Bolus sent an article,In Pharmacy, that's call'd cathartical.And on the label of the stuff,He wrote this verse,Which, one would think, was clear enough,And terse:–"When taken,To be well shaken."