This volume was printed in Paris in 1722, and as such, uses the “old music” (or some version of it) which was replaced by the modern chant editions at the end of the 19th century and beginning of the 20th; as such, it is really more of historical interest to musicians and chant scholars, and probably not of much practical use for actual liturgical celebrations. My understanding is that actually using it in the liturgy would technically be forbidden, since the modern editions were made mandatory. If anyone is an expert on these matters, please feel free to email me or leave a message in the combox as to whether these rules should still be considered in effect.
Here is the Gradual of the Mass of Holy Thursday, the famous “Christus factus est,” from the 1722 edition and the 1927 Dominican Holy Week book. (Click to enlarge.) I believe I remember aright that the version of this chant in the older. pre-Solesmes Roman Gradual had about 1/3 as many the notes as the modern version, but this does not appear to be the case here. Any comments from chant scholars on the differences would be welcome.