104 Dr T. Anderson on a Remarkable Compound 



that the same substance is also formed by treating codeine 

 with an alcoholic solution of iodine, but that it is then accom- 

 panied by much hydriodate of codeine. 



The teriodide of codeine is prepared by dissolving equal 

 weights of iodine and codeine in as small quantities of alcohol 

 as possible, mixing the solutions and leaving the mixture to 

 itself. In the course of a period varying with the degree of 

 concentration of the solution, the new compound is deposited 

 in crystals. If saturated cold solutions have been employed, 

 they begin to appear in the course of a few hours, but if 

 dilute, a longer period is required. These crystals are gene- 

 rally very small, but on one occasion I was fortunate enough 

 to obtain them of sufficient size for measurement, and the 

 numbers obtained will be found in a paper by Professor 

 Haidinger of Vienna, appended to the present notice. 



Teriodide of codeine is deposited from its solutions in small 

 triangular plates of a fine ruby red colour, by transmitted and 

 deep violet by reflected light ; these crystals are extremely 

 brilliant, with a fine adamantine, and in strong lights almost 

 metallic lustre. It is insoluble in water, but dissolves in 

 alcohol with a reddish-brown colour, and the saturated hot 

 solution deposits crystals on cooling. It is insoluble in ether. 

 Concentrated sulphuric acid has no action on it in the cold, 

 but on the application of heat it is dissolved with a deep brown 

 colour. It is slowly attacked by hot nitric acid. Treated 

 with a boiling solution of potash it is decomposed, iodine 

 being dissolved and codeine left behind. A current of sul- 

 phuretted hydrogen passed through its solution rapidly deco- 

 lorises it, sulphur is deposited, the solution becomes highly 

 acid, and on evaporation deposits colourless crystals of hydrio- 

 drate of codeine. A solution of nitrate of silver, even in the 

 cold, decomposes it instantaneously with the formation if 

 iodide of silver. 



As it is apt to lose iodine at 212°, the quantity employed 

 for analysis was dried in vacuo. The following ^are the 

 results obtained : — 



I 7*725 grains of teriodide of codeine gave 

 1,^9*020 ... carbonic acid ; and 

 I 2-283 ... water. 



