Here we have an early example of the grocer's apostrophe.
Basil Burchell was well-known not only for his Worm medicine (which was for getting rid of worms, not for making worms feel better, in case you were wondering) but also for the famous Anodyne Necklace, supposed to soothe teething babies. More about the necklace another time, but here's the part of his advertisement relating to the vermifuge:
COUGHS, COLDS, and ASTHMA's.
So prevalent at this Season of the Year.
THE famous PURGING SUGAR,
PLUMBS, for WORMS in CHILDREN and
GROWN PERSONS; or where there are no Worms,
no Medicine extant for a delicate fine purge, to free the
body from foul humours, can exceed, or even stand in
competition with them. The power of this Medicine is
truly astonishing; it purifies the blood, completely
cleanses the stomach, bowels and glands, and effectually
cures the Rheumatism, Agues, Intermitting Fevers,
Coughs, Colds, Asthmas, and a train of disorders too nu-
merous to insert, most of which are the offspring of a
foul stomach or obstructed perspiration.
For sickness, and pain at the stomach, want of appetite,
and shortness of breath, they are eminently serviceable. In
short, they have been found, on repeated trials, the best
and cheapest family medicine in the world.-Three dozen
for 2s. 8d. or a single packet of one dozen, 1s. 1½d. To
merchants, country dealers, and charitable persons, to give
away, 10s. per groce.
They have only the taste of fine sugar, and are as in-
nocent and easy to take as a common sugar-plumb
from the confectioner's.
Source: The Times, Monday 25th February 1788
Note: Apostrophe in Asthmas, comma after Sugar and spelling groce are as shown.
For a detailed study of Burchell and his publicity, you can consult A Study of Eighteenth-Century Advertising Methods by Francis Doherty, a preview of which is available on Google Book Search HERE.