In the work Untitled (1999), a glass sheet on the ground supports objects that make reference to duality: transparency and opacity, lightness and weight, subtlety and brutality. Whether broken or unimpaired, drinking glasses and other glass containers find articulation with bits of marine sponge and pieces made of iron and lead. One of them is a braid, bearing cables that connect all the elements. In this work, Tunga takes as reference the word Nigredo, Latin term for darkness used by alchemists to designate the first state of alchemy, the spiritual death, i.e., decomposition or putrefaction.

The result is a whole complex that recalls scientific experiences on energy conduction.