Implicits that are only implicitly available

implicitly1.scala

scala> object Module { 
     |   type Foo[T] = Internal.Foo[T]
     |   object Foo {
     |     def pubMethod = "Hi!"
     |   }
     | 
     |   private[Module] object Internal {
     |     trait Foo[T]
     |     object Foo { 
     |       implicit def FooString = new Foo[String] { 
     |         override def toString = "it's me!"
     |       } 
     |     }
     |   }
     | }
defined object Module

scala> implicitly[Module.Foo[String]]
res0: Module.Foo[String] = it's me!

scala> Module.Foo.pubMethod
res1: String = Hi!

scala> Module.Internal.Foo.FooString
<console>:13: error: object Internal in object Module cannot be accessed in object Module
       Module.Internal.Foo.FooString
              ^

implicitly2.scala

scala> object Module { 
     |   trait Foo[T]
     |   private[Module] object Foo { 
     |     implicit def FooString = new Foo[String] { 
     |       override def toString = "it's me!"
     |     } 
     |   } 
     | }
defined object Module

scala> implicitly[Module.Foo[String]]
res0: Module.Foo[String] = it's me!

scala> Module.Foo.FooString
<console>:13: error: object Foo in object Module cannot be accessed in object Module
       Module.Foo.FooString
              ^