589 
of Edinburgh, Session 1877-78. 
bulb A of flask 1, perfectly dry chlorine gas is passed over it, 
A being at the same time heated over a water-bath to about 
60° to 80° C. The IC1 3 , as it is formed, volatilises and condenses 
almost entirely in B, only a small portion escaping into flask 2. 
Chlorine is passed until no more iodine remains in bulb A. If the 
heating be omitted, only the outermost layers of iodine are converted 
into the trichloride, a kernel remaining unacted on. (Compare 
Christomanos , Berl. Ber. X. Xo. 5, p. 434.) 
The tubes connecting the two flasks are ground into one another 
at D, so that no cork or caoutchouc fittings are required. This is 
absolutely necessary. 
By attaching a small CaCl 2 tube to E, no moisture can enter the 
apparatus. The flasks can be weighed either together or separately. 
When passing ethylene or acetylene over either of the iodine 
chlorides, I found it best to cleanse and dry flask 2, leaving the gas 
to act on the chloride in 1. In that way any volatilised matter 
from 1 was condensed in 2, and the loss of weight was very trifling. 
By adding the required weight of iodine to the IC1 3 , and heating 
gently over a water-bath (the vessel being corked), IC1 is easily 
prepared. I invariably got it in the state of long needles.* 
Action of Ethylene (C 2 H 4 ) on IC1 3 . 
By passing pure dry C 2 H 4 over pure dry IC1 3 at 0° C., the two 
compounds chloride and chloriodide of ethylene are formed. 
This reaction takes place quantitatively, thus : — 
(C 2 H 4 ) 2 + IC1 3 = C 2 H 4 C1 2 + C 2 H 4 C1L 
grms. grms. 
Weight of flasks, 169*2 
„ +IC1 3 , .... 202*5 = 33*3 IC1 3 
„ after saturation with C 2 H 4 . 210*1= 7*6 C 2 H 4 
Theory requires 7*98 grms. C 2 H 4 . 
* It is generally stated that IC1 dissolves in alcohol and ether, forming 
yellow solution. (See Watts’s Did. of Chem. vol. iii. p. 293, new ed.) The 
fact is, that if ether (perfectly free from water and alcohol) be dropped into 
I Cl, a most violent reaction ensues. If, on the other hand, IC1 be dropped 
into a large excess of ether (or alcohol) at 0°, it dissolves, at first forming a pale 
yellow-brown solution ; but, in the course of a few minutes, the ether becomes 
darker and darker from separation of iodine. The chlorine probably acts on 
the ether to form dichlor-ether (C 4 H 8 C1 2 0) for the most part. This requires to 
be investigated. 
VOL. IX. 4 I 
