ON otKPlANT GiS. 329 



eluded ; and practical chemists are sufficiently aware of the 

 difficulty of such an exclusion, when the experiment is 

 made in the usual way. Carbonic acid gas never makes its 

 appearance, if the whole common air be previously re- 

 moved from the tube by means of a current of hidrogen, 

 and if care be taken to separate all the oxigen, with which 

 the olefiant gas may be mixed, by nitrous gas. It is proper Dissolved hj 

 to know, that liquid sulphuret of lime has the property of^'^J^^^ uretot 

 dissolving oleliant gas in considerable quantity. It cannot, 

 therefore, be used to free the gas from oxigen. 



Though the well-earned celebrity of the chemists, who 

 hate analysed olefiant gas, left little doubt, that their ana- 

 lysis was accurate, I thought it worth while to repeat their 

 ^experiments, in order to add my testimony to theirs. 



1. One ounce measure of alcohol, of the specific gra- Olefiant gaS 

 vity 0*826, and 3 ounce measures of sulphuric acid, of the ^°'^"*^*^* 

 ipecific gravity 1*860, were mixed together, and boiled in 



a small retort, almost to dryness; Ifhile the gaseous pro- 

 ducts were received in the usual manner over water. The 

 gasses obtained, (not reckoning the common air of the re- 

 tort, which amounted to about 42 cubic inches), were 146*1^ 

 cubic inches of olefiant gas,. and 53 cubic inches of carbonic 

 acid gas. The proportion of carbonic acid at first was very 

 -small, bat it increased asthe process wentow, and at the end 

 amounted to about one half of the ojefiant gas. The charry , - 

 matter which remained in the retort, after being well 

 washed and dried on a sand-bath, weighe<l 68 grains. 



2. A portion of this olefiant gas, deprived of its car- Its specific 

 'Ibonic acid, but containing 16 per cent of common air, was Si^^^^ty. 

 -found' of' the specific gra-vity '0*9786, that of air being 



* 1*000. Hence the specific gravity of pure olefiant gas is 

 0*9745. This is heavier than it was found by the Dutch 

 chemists, who state its specific gravity at 0*909. As far as 

 I know the specific gravity has not been taken before in 

 this country. ' '''^'i' * ■ 



3. Being curious to know the nature of the supposed oil, Mixed with ' 

 which is formed when olefiant gas is mixed with oximuriatic^^l^"""^^'^ 

 acid gas, 1 filled a large bottle with olefiant gas, and passed 



a current of oximuriatic acid gas into it; the wished for 

 substance soon collected at the bottom of the phial. It 

 possessed the following properties. 



(i.)it 



