Lyrics in Latin are:

THE HYMNUS EUCHARISTICUS

Te Deum Patrem colimus,
Te Laudibus prosequimus,
qui corpus cibo reficis,
coelesti mentem gratia.

Te adoramus, O Jesu,
Te, Fili unigenite,
Te, qui non dedignatus es
subire clautra Virginis.

Actus in crucem, factus est
irato Deo victima
per te, Salvator unice
vitae spes nobis rediit.

Tibi, aeterne Spiritus
cuius afflatu peperit
infantem Deum Maria,
aeternum benedicimus.

Triune Deus, hominum
salutis auctor optime,
immensum hoc mysterium
orante lingua canimus.

(Source: HERE, with sound clip sung by the Magdalen choir). The composer is:

ROGERS, Benjamin (1614-98). English composer and organist. Son of lay-clerk of St. George's Chapel, Windsor. 162u-162u: Chorister at St. George's Chapel, Windsor under Nathaniel Giles (1558-1634). 1639-41: Organist of Christ Church Cathedral, Dublin. 164u-6u: Returned to Windsor. 1660 (5th July): 'Hymnus Eucharisticus' for Guildhall Banquet for Charles II. 1661-64: Organist of Eton College. 1662-uu: Lay-clerk at St. George's Chapel, Windsor. 1664-85: Organist of Magdalen College (Oxford).
(Info from HERE)

~Masato