jquery_selector_objects.js

var $enclosure_search = $(xml).find("enclosure")

// different values for similar calls
$enclosure_search        // -> Object { 0: <enclosure>, 1: <enclosure>, length: 2, prevObject: Object, context: undefined, selector: "enclosure" }
$enclosure_search[0]     // -> <enclosure url="a">
$($enclosure_search[0])  // -> Object { 0: <enclosure>, context: <enclosure>, length: 1 } 

// Get the first enclosure tag explicitly - #attr() can no longer be called
$enclosure_search[0].attr('url')     // -> TypeError: $enclosure_search[0].attr is not a function

// jQueryify the first_enclosure variable so that #attr() can be called on it
$($enclosure_search[0]).attr('url')  // -> "a"