Most people with such interests know Dom Gregory Dix's 'purple passages' by heart. But there are other gems, evocative of times and places, little known ...
Dix cites a Gallican Preface about S Saturninus of Toulouse:
"It is very meet and right ... especially are we bound at this time to exalt with due honour the blessed Saturninus, the conclamantissimus witness of thine awful name: whom the mob of the heathen when they thrust him from the temple thrust also into heaven. Never the less thine high-priest sent forth from Eastern regions to the city of the Tolosatians, in this Rome of the Garonne as Vicar of Thy Peter fulfilled both his episcopate and martyrdom ..."
"'This Rome of the Garonne'! There is all the Frenchman's deep and tender feeling for his pays natal behind the deliciously absurd phrase. And how little French provincial catholicism has changed in its spirit and taste in all the fourteen centuries or so since this was written! The pretentious language in such homely Latin of many of these Gallican prayers is the equivalent of the heavy white marble statues, the gilt wire stands of ferns and the innumerable overwrought candlesticks and devotional bric-a-brac that express the real pride and affection of les paroissiens for the parish churches of the smaller country towns of France to this day."
And, commenting on the old Gallican Rites, Dix writes that they "plainly indicate that the end was not very far off when Charlemagne so abruptly hastened it. The barbarous boisterous Merovingian Latin in which they were composed would never have suited the clerks of the Carolingian renaissance, no Ciceros in reality but very proud of their culture, and certainly incomparably better educated than their predecessors only fifty years before. These clumsy old prayers have indeed a moving kind of poetry of their own, rather like that of the surviving fragments of the Frankish epics. But quite apart from their barbarisms of syntax and accidence, they bear very plainly written in their substance the marks of their own times, and could never have served another. ..."
Shape pp 581sqq will give you more!
As Cardinal Ratzinger pointed out, rites can die out if they fall out of use; if those who used them cease to exist.. I urge sound Catholics never to use the new Eucharistic Prayers invented in the 1960s.
Even if their promulgation was juridically valid, our disuse can consign them unde negant redire quemquam.