Vintage Hires Root Beer Extract Bottle. With Instructions.

The other side says PHILADELPHIA, PA.

Hire's Extract is still sold.  Here are the instructions for making your own root beer.

Homemade Root Beer

Carbonated with dry ice and ready to enjoy in just 15 minutes.

Making delicious homemade root beer with The Big H Root Beer Extract is as easy as ABC

1. Add sugar and The Big H Root Beer Extract to cold water and mix thoroughly in an open food-safe container. Do not cover the container with a lid while preparing root beer since pressure created may cause the container to explode.
2. Add dry ice to the mixture in a well-ventilated area and stir frequently to prevent dry ice from clumping to the bottom of the container. Continue to stir until all of the dry ice has dissolved. For root beer slushes add slightly more dry ice. (Dry ice is available at most grocery stores.) Preparation time: 15 minutes. Making the root beer is half the fun!
3. Enjoy!