Temporary restrictions on comments

I regret that I have just had to tighten restrictions on making comments across this blog.
Because one online drug vendor is currently pushing out hundreds of spam comments here each day, I have closed comments on all articles other than the most recent, in an attempt to reduce the volume of their unwanted advertising.
As soon as I can I will extend the period over which comments are accepted on older articles. I hope that will be within a few days.
My sincere apologies for having to take this action, but there’s always a few who want to ruin everything for the rest of us.