OLEFIANT GAS. 403 



comes black, froths, and emits gas, which, when it burns quietly 

 with a bright flame, may be saved ; it is received over water. 



(6.) As the mixture puffs up very much, especially towards the 

 end of the process, the heat must be very carefully managed, and 

 should never exceed that of a chafing dish. 



(c.) Sulphurous acid comes over, which the water will absorb, and 

 carbonic acid is formed, but this, as well as the other gas, is remov- 

 ed by solution of caustic alkali. 



(d.) The olefiant gas is derived from the alcohol, whose consti- 

 tution is altered by the sulphuric acid, principally, as is imagined, by 

 its uniting with the water.* 



4. PROPERTIES. 



(a.) Invisible little odor, except from sulphuric ether, which is 

 formed in the process ; I have always observed however, that it re- 

 tains the ethereal smell for a long time. Water 8 vols. absorbs 1 of 

 this gas. 



(6.) Sp. gr. 972, f air being 1. It is remarked that nitrogen gas, 

 carbonic oxide, and olefiant gas have the same gravity ; { and that 

 100 cubic inches, at the medium temperature and pressure therefore 

 weigh 29.64 grains. As it consists of 2 vols. of vapor of carbon, 

 and 2 vols. of hydrogen, its sp. gr. is easily obtained by calcula- 

 tion, thus. Twice the sp. gr. of hydrogen gas, 0694 x2 = 1388-{- 

 twice the sp. gr. of the vapor of carbon, 4166x2=8333, and this 

 number 4-1388 = .972. 



(c.) Extinguishes burning bodies, but issuing from a jet, and 

 kindled by a candle, this gas burns with extreme brilliancy, the flame 

 resembling that of the brightest lamp ; it far surpasses simple carbu- 

 retted hydrogen. 



(d.) Mixed, 1 vol. with 3 vols. of oxygen gas, and inflamed, it de- 

 tonates with great violence, and much care is requisite to avoid ac- 

 cidents. If done in glass vessels, they should be small and strong, 

 but it is better to use plate tin, or copper tubes. 



(e.) The explosion may be made in a detonating eudiometer tube, 

 by electricity, but only a cubic inch of the mixed gases should be 

 employed. 



(f.) One volume of this inflammable gas, requires 3 of oxygen for 

 saturation, and gives two volumes of carbonic acid gas. 



(g.) Dr. Henry remarks, that in order to insure the perfect com- 

 bustion of the gas, it should be mixed with 5 volumes of oxygen gas, 

 of at least 90 per cent, purity. 



* For a more particular view of the theory, see alcohol. 

 t Thomson's First Principle, Vol. I, p. 149. 



t The Dutch chemists made that of olefiant gas, .909 Dr. Henry, some years 

 ago, .967 Saussure Jr. .9852. 



