auxgm part 1

see also https://github.com/Baystation12/Baystation12/blob/dev/code/modules/xgm/xgm_gas_data.dm

code/modules/cargo/bounties/engineering.dm

@@ -4,7 +4,7 @@
 	reward = 7500
 	wanted_types = list(/obj/item/tank)
 	var/moles_required = 20 // A full tank is 28 moles, but CentCom ignores that fact.
-	var/gas_type = /datum/gas/pluoxium
+	var/gas_type = GAS_PLUOXIUM
 
 /datum/bounty/item/engineering/gas/applies_to(obj/O)
 	if(!..())
@@ -15,12 +15,12 @@
 //datum/bounty/item/engineering/gas/nitryl_tank
 //	name = "Full Tank of Nitryl"
 //	description = "The non-human staff of Station 88 has been volunteered to test performance enhancing drugs. Ship them a tank full of Nitryl so they can get started."
-//	gas_type = /datum/gas/nitryl
+//	gas_type = GAS_NITRYL
 
 /datum/bounty/item/engineering/gas/tritium_tank
 	name = "Full Tank of Tritium"
 	description = "Station 49 is looking to kickstart their research program. Ship them a tank full of Tritium."
-	gas_type = /datum/gas/tritium
+	gas_type = GAS_TRITIUM
 
 /datum/bounty/item/engineering/pacman
 	name = "P.A.C.M.A.N.-type portable generator"