Formation of IVater lij Compression y &'c. 283 



FORMATION OF WATER BY COMPRKSSION. 



In the late sitting of the National Institute, M. Biot 

 read a paper on the fommtion of water by compression 

 alone. It is known that water is composed of two kinds 

 of gas, oxygen and hydrogen, which may be combnied to- 

 gether by means of the electric spark. M. Biot has suc- 

 ceeded in making this combination, independent of elec- 

 tricity, and in rapidly compressing a mlxiure of the two 

 kinds of gas, inclosed in an air-pump. The compression, 

 by bringing the particles of gas into intimate union, makes 

 them throw out a quantity of heat sufficient to set them »ti 

 fire. Some precautions n)ust be taken in repeating this 

 experiment; as it cannot be tried without danger. Out of 

 three experiments which M. Biot n)ade, there were two in 

 which the tube of brass, which forms the pump, and the 

 pump itse'f, which was of iron, were burst by the force of 

 the explosion. 



GALVANIC EXPERIMENTS. 



Giobert, in a letter to M. van Mons, says, " I am at 

 present employed on galvanic electricity. I do not admit 

 the decomposition of water t)y the fluid of the pile. For, if 

 It be pretended that the fluid transmits hydrogen from the 

 Qne tube to the other, whv not admit also that it transmits 

 oxygen ? And in this case, the gases come from the pile, and 

 are not formed at the extremity of the wire where they are 

 disengatred. In this case, the decomposition of waser is 

 efiected in the pile, by means of the zinc ; and this circum- 

 stance may be classed among the chemical phaenomenabest 

 known. It can be easily ascertained that the gases may cir- 

 culate alona: the wires of comniunication of the pile, by 

 impregnating the interposed pieces with pure ammonia, 

 and immersing the wires, and particularly that of the nega- 

 tive pole, in a solution of alum, Vvhich will be immediately 

 precipitated by the ammonia, which will be conducted by 

 the wire. In some experiments, i caused even indigo to 

 circulate, by impregnating the pasteboard disks with a so- 

 lution of that substance in sulphuric acid. 



I found that the fluid of tlie pile burns atmospheric air, 

 giving birth to the nitric acid. It burns also a mixture of 

 hydrogen gas and oxygen. I believe that it decomposes 

 carbonic acid. In some experiments, I saw that gas en- 

 tirely disappear. The gas detonates, but I cannot yet de- 

 termine whether it be in conse([uence of the gaseous oxide 

 of carbon which is formed. 



VOLCANOES. 



