The chemical which is used to anaesthetize nematodes is

The chemical which is used to anaesthetize nematodes is Dichloro-triethyl ether.
This chemical is obsolete as a general anesthetic. It is highly inflammable and therefore incompatible with modern surgical and anesthetic techniques.
It has an unpleasant smell and irritates mucous membranes; this can cause coughing, straining, laryngeal spasm, and hypersalivation.
It is largely supplanted the use of chloroform as a general anesthetic due to ether's more favourable therapeutic index, that is, a greater difference between an effective dose and a potentially toxic dose.