added functional bunsen burner (with placeholder sprite), added capability for heated chem recipes, added preservation of data across chemical reactions for xenoarch (not sure if it actually works, seemed a bit buggy), added tungsten as a dispensable reagent for xenoarch

Signed-off-by: Cael_Aislinn <cael_aislinn@yahoo.com.au>

code/modules/research/xenoarchaeology/archaeo_chem.dm

@@ -1,6 +1,5 @@
 
 //chemistry stuff here so that it can be easily viewed/modified
-/*
 datum
 	reagent
 		tungsten	//used purely to make lith-sodi-tungs
@@ -20,18 +19,18 @@ datum
 		ground_rock
 			name = "Ground Rock"
 			id = "ground_rock"
-			description = "A fine dust made of ground up geological samples."
+			description = "A fine dust made of ground up rock."
 			reagent_state = SOLID
 			color = "#C81040" 	//rgb: 200, 16, 64
 								//todo: make this brown
 
 		density_separated_sample
-			name = "Density separated sample"
+			name = "Analysis sample"
 			id = "density_separated_sample"
-			description = "A watery paste which has had density separation applied to its contents."
+			description = "A watery paste used in chemical analysis."
 			reagent_state = LIQUID
 			color = "#C81040" 	//rgb: 200, 16, 64
-								//todo: make this white
+								//todo: make this browny-white
 
 		analysis_sample
 			name = "Analysis sample"
@@ -57,6 +56,7 @@ datum
 			result = "lithiumsodiumtungstate"
 			required_reagents = list("lithium" = 1, "sodium" = 2, "tungsten" = 1, "oxygen" = 4)
 			result_amount = 8
+			requires_heating = 1
 
 		density_separated_liquid
 			name = "Density separated sample"
@@ -74,4 +74,3 @@ datum
 			required_reagents = list("density_separated_sample" = 5)
 			result_amount = 4
 			requires_heating = 1
-*/

code/modules/research/xenoarchaeology/bunsen_burner.dm

@@ -0,0 +1,58 @@
+
+/obj/machinery/bunsen_burner
+	name = "bunsen burner"
+	desc = "A flat, self-heating device designed for bringing chemical mixtures to boil."
+	icon = 'icons/obj/device.dmi'
+	icon_state = "bunsen0"
+	var/heating = 0		//whether the bunsen is turned on
+	var/heated = 0		//whether the bunsen has been on long enough to let stuff react
+	var/obj/item/weapon/reagent_containers/held_container
+	var/heat_time = 50
+
+/obj/machinery/bunsen_burner/attackby(obj/item/weapon/W as obj, mob/user as mob)
+	if(istype(W, /obj/item/weapon/reagent_containers))
+		if(held_container)
+			user << "\red You must remove the [held_container] first."
+		else
+			user.drop_item(src)
+			held_container = W
+			held_container.loc = src
+			user << "\blue You put the [held_container] onto the [src]."
+			var/image/I = image("icon"=W, "layer"=FLOAT_LAYER)
+			underlays += I
+			if(heating)
+				spawn(heat_time)
+					try_heating()
+	else
+		user << "\red You can't put the [W] onto the [src]."
+
+
+
+/obj/machinery/bunsen_burner/attack_hand(mob/user as mob)
+	if(held_container)
+		underlays = null
+		user << "\blue You remove the [held_container] from the [src]."
+		held_container.loc = src.loc
+		held_container.attack_hand(user)
+		held_container = null
+	else
+		user << "\red There is nothing on the [src]."
+
+/obj/machinery/bunsen_burner/proc/try_heating()
+	if(held_container && heating)
+		heated = 1
+		held_container.reagents.handle_reactions()
+		heated = 0
+		spawn(heat_time)
+			try_heating()
+
+/obj/machinery/bunsen_burner/verb/toggle()
+	set src in oview(1)
+	set name = "Toggle bunsen burner"
+	set category = "IC"
+
+	heating = !heating
+	icon_state = "bunsen[heating]"
+	if(heating)
+		spawn(heat_time)
+			try_heating()