The above video is an old US Army film showing the results of testing Sarin on animals.
2-(Fluoro-methylphosphoryl)oxypropane;
Phosphonofluoridic acid, P-methyl-, 1-methylethyl ester, aka Sarin, is known to military folk as “GB”.
In the past, Sarin appealed to the military as it was very good at killing people whilst leaving buildings and infrastructure intact. Furthermore it was not persistent and therefore friendly troops could occupy the ground after a certain time.
For information about Sarin, GOTO: https://emergency.cdc.gov/agent/sarin/basics/facts.asp