592 
Proceedings of the Royal Society 
What ether remained in the above liquid;was distilled off at 35° to 40° 
in a current of C 2 H 2 . Even at this temperature a slight decomposi- 
tion occurred (iodine separating), so I stopped heating. It was 
found practicable, however, to fractionate the liquid (with very slight 
decomposition) in a current of steam. Eepeated fractionating 
yielded 
(1.) Ether + C 2 H 2 C1 2 , &c. (not examined). 
(2.) C 2 H 2 C11 4- . 
(3.) Solid C 2 H 2 I 2 . 
To ascertain the composition of the above liquid I analysed it. 
+ 0*6687 grm. ignited with pure CaO gave — 
Tube . . . 22*9350 grms. 
„ + (AgCl + Agl) 24*2482 „ 
„ + (AgCl + AgCl) 22*9207 „ 
(after converting Agl into AgCl by current of Cl). 
AgCl (on filter) . . 0*0127 grm. 
Calculated, this gives — 
Found. Theory for C 2 H 2 C1I. 
I 67*38 . . 68*77 
Cl ... 18*83 . . 17*59 
The above figures do not agree very exactly, but I had too 
small a quantity of the compound to be able to fractionate it 
perfectly. It was found impossible to determine its boiling point, 
as it decomposed very rapidly on heating, with separation of iodine.* 
Spec. Grav. . . . 2*41 at 13*5° C. 
Acetylene chlor-iodide is an ethereal liquid with much the same 
odour as the corresponding ethylene compound. Its vapour attacks 
the eyes. It does not decompose to any extent if kept in the dark. 
Remarks on Acetylene Iodide (C 2 H 2 I 2 ). 
I prepared from 50 to 60 grms. of the above compound bypassing 
the gas through a saturated alcoholic solution of iodine. As the two 
* It seemed to boil at first, on heating very rapidly, between 180° and 190° C., 
but this is not reliable. 
