>> c = Chapter.new
NoMethodError: undefined method `validates_presense_of' for #<Class:0x21697a0>
	from /Library/Ruby/Gems/1.8/gems/activerecord-2.1.2/lib/active_record/base.rb:1672:in `method_missing'
	from /Users/jacob/bookblog/app/models/chapter.rb:3
	from /Library/Ruby/Gems/1.8/gems/activesupport-2.1.2/lib/active_support/dependencies.rb:216:in `load_without_new_constant_marking'
	from /Library/Ruby/Gems/1.8/gems/activesupport-2.1.2/lib/active_support/dependencies.rb:216:in `load_file'
	from /Library/Ruby/Gems/1.8/gems/activesupport-2.1.2/lib/active_support/dependencies.rb:355:in `new_constants_in'
	from /Library/Ruby/Gems/1.8/gems/activesupport-2.1.2/lib/active_support/dependencies.rb:215:in `load_file'
	from /Library/Ruby/Gems/1.8/gems/activesupport-2.1.2/lib/active_support/dependencies.rb:96:in `require_or_load'
	from /Library/Ruby/Gems/1.8/gems/activesupport-2.1.2/lib/active_support/dependencies.rb:261:in `load_missing_constant'
	from /Library/Ruby/Gems/1.8/gems/activesupport-2.1.2/lib/active_support/dependencies.rb:468:in `const_missing'
	from /Library/Ruby/Gems/1.8/gems/activesupport-2.1.2/lib/active_support/dependencies.rb:480:in `const_missing'
	from (irb):13