2481: Octet

19 across (two words) is commonly associated with an octet. Each member of the octet defines one further unclued light.

Across

11 Masseur also kneaded old reptiles (11)
12 Country’s northern frogs, newts etc with no acid measure (7)
13 Tease one brunette, vacuous crone (6)
16 Very great network’s backing Sturgeon (7)
17 Personify old emperor and knight, judge admits (9)
18 Stare at faceless spectre (4)
21 Metal wires from Scot’s very regal people (7)
25 German scientist and short German painter (6)
26 Certain to take oral exam almost last (7)
27 Memo about area with e.g. castles they will inherit (12, hyphened)
30 Return of Spanish tennis player a long way off (4)
31 Comic novelist cups part of breastbone (9)
36 Clubs, proud, losing runs heavily (6)
37 Drawing little bottles for drink (7)
38 Criticise artist stirring tea in broadcast (11)
39 The writer said vessel carries the Venetian blind (7)

Down

2 Handle war-zone close to ravine (4)
3 Bare arms could create awkwardness in Paris (8)
4 French King Louis’s head to move turbulently (4)
5 Yoga poses fool maintains in equal quantities (6)
6 Changed coats and let the clergy wear them (8)
7 Prayer from US vocalist, not British (6)
8 Its role is to take off small clothes (4)
9 The faithless earth god in strange universe (11)
10 Measure of timber from trees, maybe (5)
14 Man in nude running quite thoughtlessly (11)
18 Gallery’s cancelling summit about European works (7)
22 Fit topless clothing for female seeking love (8)
24 Turnstones live with new song (8)
28 Carousing at sea that is introduced by crook’s girl (6)
29 Sequences of notes men use playing (6)
30 First book in church President grabs (5)
33 Invest in black caviar cakes (4)
34 Second month to bring back tropical food (4)
35 Individual in huge car (4)

A first prize of £30 for the first correct solution opened on 16 November.