Mr. Faraday on Fluid Chlorine. 413 



to avoid danger) stand at the side of the gun at a great di- 

 stance, and tie a string to the trigger, and of course must 

 not place himself either behind or before it. 



These observations are meant also to apply to fortifications, 

 where it seems that the plan would be as eifectual, or more so 

 than for ships. 



LXXXVI. On Fluid Chlorine. By Mr. Faraday, Chemical 

 Assistant in the Royal Instittition. Communicated by Sir 

 H. Davy, Bart. Pres. R.S.* 



TT is well known that before the year 1810 the solid sub- 

 -*■ stance obtained by exposing chlorine, as usually procured, 

 to a low temperature, was considered as the gas itself reduced 

 into that form ; and that Sir Humphry Davy first showed it 

 to be a hydrate, the pure dry gas not being condensible even 

 at a temperature of — 40° F. 



I took advantage of the late cold weather to procure cry- 

 stals of this substance for the purpose of analysis. The results 

 are contained in a short paper in the Quarterly Journal of 

 Science, vol. xv. Its composition is very nearly 27'7 chlo- 

 rine, 72*3 water, or 1 proportional of chlorine, and 10 of 

 water. 



The President of the Royal Society having honoured me 

 by looking at these conclusions, suggested, that an exposure 

 of the substance to heat under pi'essui'e would probably lead 

 to interesting results; the following experiments were com- 

 menced at his request. Some hydrate of chlorine was pre- 

 jiared, and, being dried as well as could be by j)ressure in 

 bibulous paper, was introduced into a sealed glass tube, the 

 upper end of which was then hermetically closed. Being 

 placed in water at 60°, it underwent no change ; but when 

 put into water at 100°, the substance fused, the tube became 

 filled with a bright yellow atmospliere, and, on examination, 

 was foxmd to contain two fluid substances : the one, about 

 three-fourths of the whole, was of a faint yellow colour, hav- 

 ing very nuich the a})pearance of water ; the remaijiing fourth 

 was a heavy bright yellow fluid, lying at the bottom of the 

 former, without any apparent tendency to mix with it. As 

 the tube cooled, the yellow atmosphere condensed into more 

 of tlie yellow fluid, which floated in a film on the pale fluid, 

 looking very like chloride of nitrogen ; and at 70° the pale 

 j)ortion congealed, although even at 32° the yellow portion 



* From tliu Pliilosojihical Transiutious for 18:J3, P;ut II. 



did 



