This old-fashioned recipe has been modified by yours truly to allow for the use of egg-white powder instead of a raw egg white.
Add sugar gradually to the egg white, work together well with wooden spoon or mixer until smooth and shiny. Add lemon juice and salt; stir well.
In using a dried egg product to make the icing, you may decrease or increase the amount of water you use to reconstitute the powder to produce a stiffer or looser icing, depending on your preference and the needs of the dish you’re making.
Note: Most cookbooks, government regulators, personal-injury lawyers, etc. tell you not to consume raw or undercooked eggs.