Normal saline (0.9% sodium chloride) traces its conceptual origin to Dutch physiologist Dr. Hartog Jakob Hamburger, who determined in an 1883 study that 0.9% was the salt concentration isotonic to red blood cells.
Hamburger’s Solution (Normal Saline): In 1896, through his in vitro studies of red blood cell lysis (osmotic fragility), he formulated a 0.9% sodium chloride solution. This eventually became the baseline for modern “normal saline” solutions used universally in medical fluid resuscitation.