Auras and Nodes is a research item accessible on the Basic Information tab of the Thaumonomicon. It teaches the player the concept of aura and introduces them to aura nodes. This research item is automatically given to all players at the start of the game.
Full text[]
The Aura is a field of magical energy prevalent throughout the world. Its origin is unclear. Some believe it is the accumulated life force of living beings, while others believe it to merely be another type of energy seeping in from some other place. The last theory seems to be most likely, as the aura is often found surrounding a node of concentrated mystical energy known as an Aura Node .
Each aura node has a base amount of magical energy it can contain and this energy is aligned to one or more aspects. It is usually aligned to Primary Aspects , but rarely a node may contain Compound Aspects .
The aspects within an aura node can be tapped by a thaumaturge for his own purposes. The simplest way to do so is with the use of a wand.
Energy that has been harvested in this manner is known as vis.
Aura nodes are hard to see with the naked eye, but faint glimmers of light often betray their presence. The Thaumometer makes nodes slightly easier to find, as looking through its lens can make them clearly visible.
Important: Caution must be taken when draining a node. There is a small chance that when a specific type of aspect within a node is completely drained, it may disappear or harm the integrity of the node.
It is possible for the node to disappear completely if all the aspects are used up.
Fortunately most nodes replenish their aspects over time and if properly maintained can provide a clever thaumaturge with all the vis he could want.
Nodes react in interesting ways to other nearby nodes and bigger nodes tend to drain the vis out of their smaller neighbors to increase their own girth.
--- Thaumonomicon