During the Winter, Elric sorts the Diedne Box 1. This is exceedingly tricky, because the magus has used a shorthand combining Latin and Celtic. Knowing the right Celtic¹, they can be translated as normal, but without it, one would be at a penalty.
There seems to be a lot of Terram spells, as one would expect from a magus living underground, quite a few of them martial. By the drawings, you have the lab texts for the enchanted items in the lab. The total volume seems to be a little smaller than Frederic's.
¹ I do not think Elric can tell the difference between p- and q-Celtic