342 Chlorine and Hydrogen. 



stfators, and no one has (so far as we are informed) indicated 

 any danger, unless the direct rays of the sun were allowed 

 to fall upon the mixture. In common with others, we have 

 been accustomed to mix these two gases, in presence of the 

 classes, and, without apprehension, to leave them to their 

 own mutual action. The result, it is well known, is the pro- 

 duction or evolution* of muriatic acid; which, when the ves- 

 sel stands over water, or is opened in contact with that fluid, 

 is instantly absorbed. 



Being aware of the danger arising from the mixture of 

 chlorine and hydrogen gases, when exposed to the sun's 

 direct rays, we have been sufficiently cautious on that head. 

 In one experiment, we mingled, in equal volumes, about 

 three quarts of the gases; they were introduced, — first the 

 hydrogen, and then the chlorine, — into a strong flask of 

 green glass: the vessel was wrapped in a thick coarse towel, 

 corked, and laid on the snow, (January, 1820,) by the side 

 of a brick wall, where the sun's meridian rays were received 

 without any interposing obstacle. We now removed the towel, 

 with all possible speed, and ran to the distance of thirty feet ; 

 where we had just time to observe marks of a powerful action, 

 as evinced by a white fume, rapidly undulating through the 

 flask, when it exploded, with great force, and a violent re- 

 port, reducing the glass to very small fragments, some of 

 which struck us, as well as other observers. 



The present season, (February 16, 1821,) being desirous 

 of showing this interesting experiment to the pupils, the gas- 

 es were, in the presence of the classes, mixed as before, in 

 a similar vessel, and in about the same quantity. The audi- 

 ence, consisting of two hundred, or more, formed a large cir- 

 cle, out of doors : the flask was placed in a wooden box, which 

 was carried into the sun's rays ; then, by hand, we suddenly 

 threw up the lid, and slipped into a contiguous door of the 

 laboratory. There was scarcely time to escape, and, indeed, 

 hardly an appreciable interval of time, before the explosion 

 occurred, with such violence, as not only to rend the glass, 

 but to blow the box into pieces, which were thrown all 

 around. 



* According as the phenomena ar^ explained by tlie new or the old thebf y. 



