Mods/Thaumcraft/Crucible

The crucible is a basic tool of Thaumcraft, allowing the manufacture of several special materials, and the production of various metals from raw essentia. The crucible is created by placing a cauldron and right-clicking it with a wand of any type. The cauldron will be permanently transformed into a crucible, which can then be picked up (by mining it with a pickaxe) and placed elsewhere like any other block.

Advanced players can build a Thaumatorium. This wondrous device allows automating any crucible recipe without the various risks listed below, but except for the catalyst, it requires purified essentia rather than the items containing it.

Use
For use, a crucible needs to be placed over some heat source, and filled with water. This can include a fire block (such as from burning netherrack), a lava block, or the magical flame Nitor. Once the water begins boiling, the crucible is ready for use. (Note that the water will be partially consumed with each recipe.) Having researched a recipe, you can use it by throwing in items to be broken down into the essentia needed by the recipe (phials work fine), and immediately following this with the recipe's "catalyst" item. The result will appear immediately, and if you are close enough will be added to your inventory. For speed, use the control key with your "drop" command (default ) to throw a pre-counted stack of items all at once. There are many hazards to crucible work:
 * You must have researched the recipe, or your catalyst will simply be dissolved with everything else, leaving you with a cauldron full of mixed essentia.
 * You need to avoid "accidental" triggering of other recipes. This becomes much more of an issue with the recent introduction of many utility recipes, notably entropic processing and nugget duplication.  Some tips:
 * When using cobblestone as an unrefined Perditio source, craft it into stairs first to avoid generating gravel (you get more Perditio this way, too).
 * When using iron nuggets for Metallum, add them last to avoid the iron-duplication recipe.
 * Recipes can (and sometimes must) be done in multiple, but be careful not to overload the cauldron, lest it overflow (see below).
 * If essentia is left in the cauldron more than a few seconds, it will begin to break down, point by point. Compound aspects will break down into their components, while primal aspects will vanish and produce flux (see below).  Naturally, this will spoil many recipes.
 * If a crucible is loaded with too much essentia, or essentia is left to break down, it will overflow with liquid and/or gaseous flux. It will also release flux if it is explicitly emptied by right-clicking with a wand.
 * Gaseous flux will float up to the ceiling, possibly tainting the blocks there. If there is no ceiling, it will float up into the sky and dissipate harmlessly.
 * Liquid flux will flow over the area. If there is enough of it, it can form ../Thaumic Slime/s, aggressive mobs which can grow to amazing size depending on how much flux is present for them to absorb.
 * If liquid flux is left sitting for long enough, it has a faint chance of tainting the area.
 * Both gaseous and liquid flux are difficult to handle; they can be destroyed only by replacing their block with another block, such as dirt or a water source. Note that flowing water will hide the flux it flows over, but not destroy it.
 * Throwing a loaded wand into a crucible will produce a lot of flux, and huge Thaumic Slimes!

Flux Farming
Advanced players can use a crucible to farm Thaumic Slimes, for both experience and their "tainted goo" drops. The drops are difficult to handle (if kept in a player's inventory, they will slowly dissolve over time, tainting the player with each dissolution), but they are the primary source of the otherwise-rare aspect Vitium. For Flux farming, the crucible should be placed in a large pit, at least 4 blocks deep and 9 or more across. The pit should be placed well away from lairs or any other territory that might be at risk. It should also be equipped with several safety features: An escape tunnel with a door (and a pressure-plate to close it behind you), hoppers or chests to collect flux goo, and several Brains In a Jar to collect the multitude of experience orbs, and thus prevent them from producing lag. Optional features include a flood system to wash drops into hoppers (be warned this can merge little slimes into big ones), and even a system to remotely drop TNT into the pit. (If you use TNT, the floor needs to be obsidian and/or flooded to protect the BIJs and other equipment. The cauldron is probably a write-off for this case....)  Also, suitably arranged alcoves can let you fight the smaller slimes up close, while screening out the larger ones. For arms and armor, A wand with several offensive foci will be useful for fighting the big slimes, and a Thaumostatic Harness is also useful for escape or firing from a distance. Thorns-enchanted armor and a Sword of the Zephyr will both help against the smaller slimes.

Once the flux farm is set up, fill the cauldron with water, and dump in a bunch of trash -- anything will do, as long as there's enough to overload the cauldron. And let the battle begin! Once you have finished off the slimes, use blocks to remove any remaining flux. Then check the blocks for possible taint, and mine any tainted blocks to prevent it from spreading (unless, of course, you're trying to create a tainted area!)