README.md in eulim-0.0.4 vs README.md in eulim-0.0.5

- old
+ new
@@ -37,16 +37,20 @@
 #### Compound
 
 ## Usage
 
 	$ Eulim::Chemistry::Element.get_by_symbol("H")
-	=> #<Eulim::Chemistry::Element:0x0055ac58c146e8 @symbol="Mg", @name="Magnesium", @atomic_number=12, @atomic_mass=24.305>
+	=> #<Eulim::Chemistry::Element: @symbol="H", @name="Hydrogen", @atomic_number=1, @atomic_mass=1.008>
 
 	$ Eulim::Chemistry::Element.get_by_atomic_number(12)
-	=> #<Eulim::Chemistry::Element:0x0055ac58c146e8 @symbol="Mg", @name="Magnesium", @atomic_number=12, @atomic_mass=24.305>
+	=> #<Eulim::Chemistry::Element: @symbol="Mg", @name="Magnesium", @atomic_number=12, @atomic_mass=24.305>
 
-	$ Eulim::Chemistry::Compound.constituent_elements("CaCO3")
-	=> [#<Eulim::Chemistry::Element:0x0055c971365598 @symbol="Ca", @name="Calcium", @atomic_number=20, @atomic_mass=40.078>, #<Eulim::Chemistry::Element:0x0055c9713652c8 @symbol="C", @name="Carbon", @atomic_number=6, @atomic_mass=12.0107>, #<Eulim::Chemistry::Element:0x0055c971365048 @symbol="O", @name="Oxygen", @atomic_number=8, @atomic_mass=15.9996>]
+	$ Eulim::Chemistry::Compound.new("CaCO3")
+	=> #<Eulim::Chemistry::Compound: @formula="CaCO3">
+
+	$ Eulim::Chemistry::Compound.new("CaCO3").elements
+	=> [#<Eulim::Chemistry::Element: @symbol="Ca", @name="Calcium", @atomic_number=20, @atomic_mass=40.078>, #<Eulim::Chemistry::Element: @symbol="C", @name="Carbon", @atomic_number=6, @atomic_mass=12.0107>, #<Eulim::Chemistry::Element: @symbol="O", @name="Oxygen", @atomic_number=8, @atomic_mass=15.9996>]
+	
 ## Development
 
 After checking out the repo, run `bin/setup` to install dependencies. Then, run `rake spec` to run the tests. You can also run `bin/console` for an interactive prompt that will allow you to experiment.
 
 To install this gem onto your local machine, run `bundle exec rake install`. To release a new version, update the version number in `version.rb`, and then run `bundle exec rake release`, which will create a git tag for the version, push git commits and tags, and push the `.gem` file to [rubygems.org](https://rubygems.org).