Will an EU referendum kill the Scottish independence referendum?

The UK faces two referendums about its future, not one.  As well as David Cameron’s promised ‘proper’ referendum on the UK’s relationship with the European Union, there is also the one on Scottish independence due on 18 September 2014.  By and large, despite similarities in the arguments involved, each of those debates has paid little regard to the other.  That makes sense if the EU referendum takes place in the next UK Parliament, around 2017 or so, once the dust has settled on the Scottish vote.  Suggestions of an earlier referendum may throw that into doubt.  The dynamics of the debate about Scottish independence would look very different if the EU poll were held before the Scottish one. 

What would happen if there were an ‘English’ vote against the European Union, while majorities in Scotland (and perhaps Wales and Northern Ireland) voted to stay in?  That’s a perfectly realistic scenario: political debate generally in Scotland is much more pro-EU than in England, and opinion