SS
Sorry - you're right - half remembered information.
Here is the ref. I was thinking of from Opie's Dictionary of Rhymes.

Ring-a-ring-o' roses,
A pocket full of posies,
A-tishoo! A-tishoo!
We all fall down.
The words of this little ring-song seem to be becoming standardized though this was not so fifty years ago when Lady Gomme was collecting (ante 1898). Of the twelve versions she gathered only one was similar to the above. Although 'Ring-a-ring o' roses' is now one of the most popular nursery games—the song which instantly rises from the Ups of small children whenever they join hands in a circle—the words were not known to Halliwell, and have not been found in children's literature before 1881. Newell, however, says that,
Ring a ring a rosie, A bottle full of posie, All the girls in our town, Ring for little Josie,
was current to the familiar tune in New Bedford, Massachusetts, about 1790. The 'A-tishoo' is notably absent here, as it is also in other versions he gives, in which the players squat or stoop rather than fall down:
Round the ring of roses,
Pots full of posies,
The one who stoops last Shall tell whom she loves best.
The invariable sneezing and falling down in modern English versions has given would-be origin finders the opportunity to say that the rhyme dates back to the days of the Great Plague. A rosy rash, they allege, was a symptom of the plague, posies of herbs were carried as protection, sneezing was a final fatal symptom, and 'all fall down' was exacdy what happened. It would be more delightful to recall the old belief that gifted children had the power to laugh roses (Grimm's Deutsche Mythohgie). The foreign and nineteenth-century versions seem to show that the fall was originally a curtsy or other gracious bending movement of a dramatic singing-game, and the present writers have on several occasions gathered from oral tradition a sequel rhyme for the players to rise on their feet again,
The cows are in the meadow Lying fast asleep,
A-tishoo! A-tishoo! We all get up again.
Lines similar to these last are also known to the Irish Celts.
Mother Goose, Kate Greenaway, 1881, 'Hush! hush! hush! hush! We're all rumbled down' / Shropshire Folk-Lore, (5. F.Jackson, 1883, 'One for Jack, and one for Jim, and one for little Moses—A-tisha! a-tisha! a-tisha!' also varia ending 'A curchey in, and a curchey out, And a curchey all together' / Newell, 1883, as quotes / Sheffield Glossary, S. O. Addy, 1888, varia / Gomme, 1898, varia including 'Ring a ring o' roses, A pocket-full o' posies; One for me, and one for you. And one for little Moses—Hasher, Hasher, Hasher, all fall down' / Mother Goose, Arthur Rackham, 1913 / What the Children Sing, Alfred Moffat, 1915, 'A ring, a ring o' roses, A pocket full of posies, Ash-a! Ash-a! All stand still. The King has sent his daughter To fetch a pail of water, Ash-a! Ash-a! All bow down. The bird above the steeple Sits high above the people, Ash-a! Ash-a! All kneel down. The wedding bells are ringing, And boys and girls are singing, Ash-a! Ash-a! All fall down' / Oral collection, 1947, as quote.
Cf. Folk-lore, 1882, 'Here we go round by ring, by ring. As ladies do in Yorkshire; A curtsey here, a curtsey there, A curtsey to the ground, sir' / Deutsches Kittderbuch, Karl Simrock, 184S, 'Ringel, Ringel Reihe! Sind der Kinder dreie. Sitzen auf dera Holderbusch, Schreien alle musch musch musch: Sitzt nieder! Sitzt ne Frau im Ringelein, Mit sieben kleinen Kinderlein. Was essens gerne? Fischlein. Was trinkens gerne? Rothen Wein. Sitzt nieder!', also rhyme beginning 'Ringel Ringel Roscnkranz' / Alemannisches Kinderlied, E. L. Rochholz, 1857 / Reime der Kinder in Oesterreich, T, Vernaleben, 1873 / Chants Populate du Languedoc, L. Lambert, 1906, 'Branle, calandre, La Fille d'Alexandre, La peche Men mure, La figue bien mure, Le rosier tout fleuri, Coucou toupi! — En disant "coucou toupi", tous les enfants, qui forment la ronde, s'accroupissent' / American Folk Lore, 1897, Swiss, 'Randin, picotin, La Marie a fait son pain, Pas plus gros que son levain. Pugh! dans l'eau.' Last one down is it j Children's Games throughout the Year, L. Daiken, 1949, from County Donegal, 'Here we go round the Jingo Ring, Jingo Ring, Jingo Ring, Here we go round the Jingo Ring And the last pops down!' Also cf. the Gaelic 'Bulla! Bulla! Baisin, Ta'n bo sa guirdin. Sios libh !Sios libh! Eirigidh anois, Eirigidh! Deanam aris 6. (Clap! Clap! Hands, The cow is in the garden. Down ye go! Down ye go! Get up now, get up! Let's do it again.)'
Parody: The Observer, 9 Jan. 1949, 'Ring-a-ring-o'-geranium, A pocket full of uranium, Hiro, shima, All fall down.