COMBUSTIBLE GASES. 
173 
part of the State. Although it often passes through water, it is but sparingly absorbed by it. 
Its origin, like that of many of the other gases which are evolved from the surface, is probably 
deep seated. 
SULPHURETTED HYDROGEN. 
Sulphuretted Hydrogen Gas. Cleaveland. — Sulphuretted Hydrogen. Shepard. — Schwefliges Hydrogen-Gas. 
Mohs. — Hydrogene Sulfure. Beudant. 
Description. Gaseous, colourless, transparent; absorbed by water. It has a very offen¬ 
sive taste and odour resembling that of rotten eggs, by which it can be distinguished from all 
other gases. It is heavier than atmospheric air, its specific gravity being 1177, and that 
of air 1000. 
This gas is highly inflammable, and burns with a pale blue flame; but it extinguishes burning 
bodies, and cannot be safely breathed in any quantity. With oxygen gas it forms a mixture 
which detonates by the application of flame, or by the electric spark. It blackens the salts of 
lead, and many other metallic compounds. 
Composition. Sulphur 94.18, hydrogen 5.82. It contains, therefore, one atom of each 
of the constituents. Its formala will be SH. 
Uses. In addition to the medical virtues which are ascribed to this substance, it is an ex¬ 
tremely useful reagent in the laboratory. It is employed in the gaseous form, in solution in 
water, and in combination with ammonia as a test for the metals. 
LOCALITIES. 
This gas is abundantly evolved in various parts of the State, and it forms what are called 
Sulphureous , Sulphuretted or Hydrosulphuretted Springs. Of these, a detailed notice, to¬ 
gether with an examination of the theory of their origin, will be found in the first part of this 
work (page 141). 
PHOSPHURETTED HYDROGEN. 
Phosphoriges Hydrogen-Gas. Mohs. 
Description. Gaseous, transparent, colourless; sparingly absorbed by water, 
offensive smell resembling that of garlic. Its specific gravity is 1185, compared 
1000. 
This gas does not support flame or respiration, but is characterized by inflaming 
ously when mixed with air or with oxygen gas. 
Composition. Phosphorus 91.29, hydrogen 8.71, or one atom of the former and three 
atoms of the latter. Its formula is PH 3 . 
It has an 
to air as 
spontane- 
