EXPLOSIVE GAS GENERATED— MACKAY. 375 



with the circulation of the water through the coils, when anthra- 

 cite coal was used than when bituminous coal was used. The 

 water was also more prone to " boil " in the furnace in these 

 cases, from the greater heat of the anthracite. I have not the 

 time and conveniences now to make an accurate analysis of the 

 gas. My investigation is only preliminary, and my object in 

 bringing it now before the Institute is to stimulate the collection 

 of other observed facts in connection with the phenomena. 

 Roughly then, we can here observe the following reactions of 

 our gas. 



1. By uncorking these small bottles you can observe the 

 peculiar naptha-like odor characteristic of the gas. This sug- 

 gests the presence of at least a small portion of some hydro- 

 carbon. 



2. I now remove the stopper from this large inv erted glass 

 jar, and placing this lighted candle to its mouth we find it takes 

 fire and burns at the mouth of the jar like so much pure hydro- 

 gen Putting the candle up into the jar above the pale, blue 

 fire plane separating the outside air from the gas within, the 

 light is extinguished. The gas cannot support combustion. We 

 readily relight our candle, however, at the nearly invisible flame 

 yet playing at the mouth of the jar. The blue flame has quite 

 an intense heat. See, the mouth of the jar cracks. A drop of 

 water rolling down its inside to the mouth of the jar, heated 

 nearly to redness, is responsible for this. 



3. I now apply a light to this jar containing two parts of the 

 gas and five parts of air. We have a gentle explosion with the 

 usual pale flame, and the sides of the jar are temporarily be- 

 dewed. Let us next in the same manner fire this strong, wide 

 mouthed jar wrapped in a towel to prevent danger from flying 

 glass should the shock of the explosion be too much for its 

 strength. We liave it in two parts ofour gas with one part of 

 oxygen. The report of the explosion is deafening. Is it pure 

 hydrogen ? 



. 4. Here is some transparent lime water. I pour some of it 

 into this transparent glass jar. I shake up the lime water with 



