In this link, you can see the same photograph from Vincendeau as shown in the PK article linked in reply 21 but with the original French annotation.
https://www.1stdibs.com/en-gb/furniture/more-furniture-collectibles/collectibles-curiosities/books/les-opalines-christine-vincendeau-first-edition/id-f_6444953/?modal=intlWelcomeModalFrench annotation:
Flacon de cheminée tricolore et son bouchon fleur en opaline jaune et blanche « pâte de riz»
décor moule par soufflage, dit « à grenade éclatée», décor rapporté en opaline bleue figurant un serpent s'enroulant autour du col au bord ondulé (doc. Compagnie des cristalleries de Saint-Louis). Manufacture de Saint-Louis.
Années 1845-1855.
Annotation Google translated:
Tricolor chimney flask and its flower stopper in yellow and white opaline “rice paste”
decoration molded by blowing, called "exploded pomegranate", decoration added in blue opaline depicting a snake winding around the neck with a wavy edge (doc. Compagnie des cristalleries de Saint-Louis). Manufacture of Saint-Louis.
Years 1845-1855.
Presumably “doc. Compagnie des cristalleries de Saint-Louis” is the original source, a document from the company?
For reference, Google translating the annotation from PK:
"Tricolor chimney flask ... in yellow and white opaline rice paste, decoration molded by blowing [form-geblasen], said with exploded pomegranate ... snake winding around the neck aus Vincendeau 1998, S. 88
St. Louis, Frankreich, 1845-1855