Prof. Johnston on the Iodide of a new Carlo-hydrogen. 5 



The water in the chloride of calcium tube reddened litmus, 

 indicating the presence of muriatic acid, by which the weight 

 of water would be in some measure increased. 



b. 7*61 grs. heated with dry carbonate of soda, gave 7'033 

 grs. of chloride of silver or 22*8 per cent, of chlorine. 



c. 4*462 grs. heated in like manner, but with more care, 

 gave 4-517 grs. of chloride of silver or 24*12 per cent, of 

 chlorine. 



These results give for the composition of the yellow matter 



A B 



Carbon... = 61*55 = SO atoms. 



Hydrogen 5'98 ]7'8 



Chlorine... 24-12 22*8 2*02 



Oxygen ... 8*35 3*11 



100 



This result indicates the irrational formula C 30 H 17 CI 2 O 3 , 

 which gives 



30 carbon = 2293-11 = 62-13 per cent. 



20 hydrogen 212-15 5'75 



2 chlorine 885-30 23'99 



3 oxygen 300*00 8-13 



3690-56 100- 



The elements contained in the above irrational formula are 

 capable of being arranged in several rational positions. 

 The green iodide being C 30 H 20 + I, 



The yellow substance may be (C so n 17 +C1) + C1 (1), in 



^3 



which three of hydrogen are replaced by three of oxygen, the 

 atom of iodine by one of chlorine, and the whole combined 

 with another atom of chlorine the oxygen being derived from 

 the alcohol, which was undergoing a simultaneous decomposi- 

 tion by the action of chlorine. 



Or, it may be C 30 ^ 16 O 3 +H Cl . . . (2.) 



TCI* 

 Or CgJ H 16 +HO . . (3.) 



Lo 2 



in both of which the principle of substitution is equally 

 evident. Were we to represent the green compound by 

 Cgo H 20 -f H I, there would even be a conservation of the ori- 

 ginal type of composition *. This type may also be supposed 

 to be sufficiently preserved in the radical, and that it is owing 



[* See the memoir of M. Dumas, p. 442 of the last volume. EDIT.] 



