Talk:Thornmail/@comment-184.153.51.139-20120723050820/@comment-4881935-20120730161142

rule of thumb for items, items don't proc other items.

here's a list that shows u that it doesn't proc the slow: http://leagueoflegends.wikia.com/wiki/On-hit_effect#Items

Go to the last one to find it.

Also, it is not a requirement that the damage has to be magic damage to slow the target, it just has to come from an ability in order to proc the slow.