No Context Given: Justice League of America #72

From Justice League of America #72 by Dennis O’Neil and Dick Dillin

“So, he’s composed entirely of NaCl now,” mused the Batman, unhelpfully.
“Not helpful,” said Hawkgirl. “This is serious, you nerd.”
“As a heart attack,” added Superman.
Batman nodded. “Right. Because of all the NaCl.”