GAS. 



oil on coming into contact with oxygenat- 

 ed muriatic acid gas. If five measures be 

 mixed with six of the oxygenated muria- 

 tic gas, as rapid a dimunition takes place 

 as when nitrous and oxygen gases are ad- 

 ded to each other, and a thin film of oil 

 forms on the surface of the water. 



Mr. Henry examined these and some 

 other varieties, as well as pure hydrogen, 

 with a particular view to the light they 

 were capable of affording; and the fol- 

 lowing arc his tabulated results : 



The light evolved appeared to be in 

 proportion to the oxygen consumed, so 

 thai the first four in the list yielded very 

 little; but the last much exceeded all the 

 rest. Its detonation with oxygen gas too 

 is more violent than that of any other in- 

 flammable gas .03 of a cubic inch, with 

 17 ot oxygen gas, being sufficient to burst 

 a strong glass tube. 



About the year 1792, Mr. Murdoch 

 made various experiments on the gas from 

 coal, peat, and other substances, as a sub- 

 stitute for lamps and candles, both as^fix- 

 ed and as moveable lights, and in 1793 he 

 applied it to the purpose of lighting the 

 extensive manufactory at Soho. Light was 

 procured by the same means several years 

 ago at the ovens in Shropshire, for pre- 

 paring coke and tar, on LordDundonald's 

 plan. And six or seven years since a pro- 

 jector at Paris lighted up his house and 

 gardens, and proposed to light the streets 

 of the city in a similar way. 



The varieties above enumerated differ 

 in specific gravity, the olefiant gas being 

 the heaviest, and that from charcoal the 

 lightest. They differ likewise in the 

 quantity absorbed by water, which takes 

 up one-eighth its bulk of olefiant gas, one- 

 sixty -fourth of that from stagnant pools, 

 and still less of the others. 



G\s. phosphuretted hydrogen. This may 

 be procured by boiling in a retort a little 

 phosphorus, with a solution of pure pot- 



ash. The phosphorus should be first melt- 

 ed under water in the retort, which is to 

 be emptied when the phosphorus has con* 

 gealed, and then filled with the alkaline 

 solution. Of this a sufficient portion is to 

 be displaced by hydrogen gas. Or one 

 part of phosphorus, cut into very small 

 pieces, and two of finely granulated zinc, 

 may be put into ten parts of water, and 

 six parts of concentrated sulphuric acid 

 added; the gas is disengaged in small 

 bubbles, which cover the whole surface of 

 the fluid, and take fire on reaching the 

 air, so as to form by their succession a 

 well of fire. 



If two parts of phosphuret of lime, bro- 

 ken into pieces the size of a pea, and one 

 of hyperoxymuriate of potash be put into 

 an ale glass, or a Florence flask, the ves- 

 sel be filled with water, and six or eight 

 parts of concentrated sulphuric acid be 

 poured in through a long-necked funnel 

 reaching to the bottom, as soon as de- 

 composition commences, flashes of fire 

 will dart from the surface, and the bottom 

 of the vessel will be illumined with a 

 beautiful green light. 



When phosphuretted hydrogen gas is 

 suffered to escape into the air, as it is- 

 sues from the retort it takes fire, and a 

 dense white smoke arises, in the form of a 

 horizontal ring, enlarging its diameter as 

 it ascends. It detonates when mixed sud- 

 denly with oxygen, oxygenized muriatic 

 acid, or nitrous oxide gas. By standing it 

 loses its property of spontaneous ascen- 

 sion, the phosphorus being deposited on 

 the inner surface of the vessel containing 

 it. 



Phosphuretted hydrogen gas may be 

 dissolved in about four times its bulk of 

 distilled water, at 44 Fahrenheit, and 

 imparts to it a bitter taste, and strong un- 

 pleasant smell. This solution speedily 

 converts the oxides of lead and mercury, 

 and nitrate of silver, into phosphurets of 

 those metals. Nitrates of lead, mercury, 

 and arsenic, and sulphates of copper and 

 iron, are acted upon by it more or less 

 slowly ; but some of the posphurets then 

 formed are changed, by standing some 

 time, into phosphates. 



The ignis fatuus, or jack with a lan- 

 tern, is supposed to be produced by this 

 gas, arising from the putrefaction of ani- 

 mal substances in swampy places. 



GAS, sulphuretted hydrogen. This gas, 

 formerly teamed hepatic air, may be ob- 

 tained, by adding dilute muriatic acid to a 

 solution of sulphuret < f potash or of soda, 

 which evolves it with violent efferves- 

 cence ; or by pouring diluted sulphuric or 

 muriatic acid on sulphuret of iron. SuV 



