Inquisitor 1301

[Ripper]

Please can some kind person help me with two clues & explain the wordplay:
18 across Base makes this clue literally about height (6) _I_MU_
8 down: Glossy magazine mostly about a Frankish tribe (5) SA_IC
I think the answers may be Litmus & Salic but have no idea why.
Also the letters to highlight, am I correct that it's just seven of them?
Thanks in advance

[dannyk13]

8d.Glossy mag = Slic(k) about a.

[ulysses100]

I couldn't fully parse 18a either, but the misprint is clue to blue, and literally is probably "lit"
There are eleven squares to highlight.

[Neveracrossword]

I too don't know how 'litmus' works, sorry. I no longer have the paper, but I'm sure the highlighting was more than seven letters - it was two words. I think there might be more discussion on the other Inquisitor thread.

[boreas]

Ripper,

Google 'litmus base' or 'acid base' and this should help explain.

[boreas]

LIT= abb. of literally.
MUS = SUM (height) about.

[Ripper]

Thank you everyone!