At the time of investigation of any chemical process a person strives to use the reactor, which is small by its size, well isolated from environment and has possibility of regulation. That gives a possibility to match the quantitative measuring of material and energetic changes for the system, which we investigate. That is very necessary in order to have a real presentation about the process. However, in nature the processes go on the large distances and have the direct link with the environment. In these cases the system is considered open and nonavailable for quantitative investigations. In this sense the caves and the processes that go in the caves have the special case The cave can be considered as a reactor that has large size, constant temperature and isolated from the environment [58].

The chemical reactions, which go in the caves, almost always are in equilibrium state. In spite of the rate of chemical process, it reaches to equilibrium state, because it is almost close and there is not limits of time. The investigation of the processes, that go in that conditions are very interesting not only for chemistry but for its neighbour sciences, in particular for biology. It is known, that the caves are used as an environment which has the curative microclimate for many illnesses.

During the last years investigation of cave chemistry has a big progress. The valuable results have been received, which can explain many different processes, which run in the caves [25].However many processes need deep analysis. We make an attempt to use that results, which are going on the interface of gas- solid for explanation of any cave processes.

One of the classes of chemical reactions, which can have an interesting point of speleochemistry and speleotherapy is the chemical interaction between the hydrogen peroxide and cristalic material, in result of which some interesting phenomena are observed. The presence of H₂ O₂ in cave air can be presented in various manners. We have not a purpose to discuss all the possibilities in details. Note only, that it can be formed in the caves. Also note , that those chemical processes which from our point of view can be interesting in the cave processes, go in the presence of very small quantity of H₂O₂ ( H₂O₂ : air = 10^-5 ). So the presence of intangible quantity of H₂O₂ in the cave can lead to some process. In order to imagine the nature of possible reactions of H₂O₂ on the solid surface we briefly discuss some peculiarities of the mechanism of hydrogen peroxide vapour heterogenous decomposition. The results are received by complex investigation of kinetic regularities of molecular substances and intermediate active particles( the radicals and the ions) [54 - 56, 59, 60].