Who would have thought that doctors figured out intravenous treatments for cholera before they figured out to give people water with sugar and salt?

Salt, Sugar, Water, Zinc: How Scientists Learned to Treat the 20th Century’s Biggest Killer of Children—Asterisk
Oral rehydration therapy is now the standard treatment for dehydration. It’s saved millions of lives, and can be prepared at home in minutes. So why did it take so long to discover?
asteriskmag.com