bicarbonate of soda
From The Food Lover's Companion, Fourth edition by Sharon Tyler Herbst and Ron Herbst. Copyright © 2007, 2001, 1995, 1990 by Barron's Educational Series, Inc.
Homemade soda is just a mix of flavored syrup and seltzer or club soda. Adjust the ratio depending on how sweet you like it.
If you have a hankering for an ice cream parlor treat, nothing beats an ice cream soda. All you need is a straw (or two), a glass, ice cream, soda and syrup, and you've got the makings of one of the great ice cream classics.