Here is only short description of mask anaesthesia by dripping volatile anesthetics as nowadays it is still applied only in developing countries. Special schimmelbusch mask, covered with several beds of gauze is applied at the patient's face. Then high-volatility anaesthetic is dripped on it (as a rule - aether or halothanum). During an inspiration air transits through a gauze and, having sated with anaesthetic pairs, arrives in respiratory airways. Transpiration of an anaesthetic decreases mask temperature that leads to condensation of moisture. This also decreases the pressure of a saturated anaesthetic gas (saturation pressure is directly proportional to temperature).

The anaesthesia excavation reduces minute ventilation that leads to a vicious circle development: the mask is warmed, saturation pressure increases, concentration of anaesthetic in an inhaled admixture rises dramatically.

If a considerable quantity of carbon dioxide is accumulated behind a mask (so called apparatus "dead space"), then a great part of exhaled admixture returns in the respiratory airways. Besides, anaesthetic pairs reduce fractional concentration of oxygen in an inhaled admixture (dilution effect) that frames hazard of a hypoxia. In order to reduce "dead space" and to raise fractional concentration of oxygen in an inhaled admixture, it's useful ­to deliver additional oxygen under a mask.

The last disadvantage of dripping volatile anesthesia is contamination with anaesthetic pairs, that can be dangerous for their flammable properties (aether).