Preheat the oven to 400˚F (200˚C). Line 2 baking sheets with parchment paper.
Pour the sugar into a baking dish and slide it in the preheated oven for about 4 minutes, until the sugar is hot to the touch. Remove from the oven and reduce the temperature to 225˚F (110˚C).
In the bowl of a stand mixer or with a handheld electric mixer, whisk the egg whites and salt until foamy.
Quickly tip all the hot sugar into the bowl and whisk on medium-high speed until the meringue is very thick, super glossy, and white, 6 to 8 minutes. The meringue should hold soft peaks and, if you're feeling bold and are so inclined to turn the bowl upside down and hold it over your head, the meringue should stay put.
Spoon the meringue into the piping bag or spoon it into a large resealable plastic bag and snip off 1 of the bottom corners. Pipe a strip about 4 inches long on the baking sheet. Pipe 2 small blobs of meringue on each end of the log to make a bone shape. It may take a couple of practice tries to get them to look the way you want. Repeat, spacing the bones a decent distance apart from each other.
Bake the meringue bones for about 40 minutes, until crisp and dry to the touch. (The larger your bones, the longer it will take for them to turn crisp and dry.)
Turn the oven off but leave the bones inside until they cool to room temperature. The meringue bones will keep in an airtight container for 1 to 2 days.