Iodine for Hydrogen in Organic Compounds, 207 



yellow colour and brilliant lustre, and having an odour re- 

 sembling that of saffron. It is insoluble in water, soluble 

 in alcohol, especially on boiling, and in aether. It is insoluble in 

 hydrochloric acid, and may be boiled with that reagent without 

 suffering decomposition. Strong nitric acid attacks it with great 

 violence, but does not effect a complete oxidation of all the 

 iodine. It is unacted on in the cold by strong sulphuric acid, 

 but if heated, it is decomposed with the liberation of iodine. 

 Caustic potash when long boiled with it, removes a very small 

 quantity of iodine. It does not affect litmus paper, and seems 

 to possess neither acid nor basic properties. It sublimes un- 

 altered at a temperature greatly below that of boiling water. 



These characters closely approximate to those of iodoform, and 

 I at first considered it to be that substance. The analysis, how- 

 ever, made with every care, and on specimens prepared at dif- 

 ferent times, gave results which cannot be made to agree with 

 the formula of that substance. 



The analyses are as follows : — 



I. 7-141 grains substance, air-dry, gave 0-913 grains carbonic 

 acid and 0*913 grains water. 



II. 4-365 grains substance, air-dry, gave 4*365 grains car- 

 bonic acid and 0*164 grains water. 



III. 8*153 grains substance, air-dry, gave 0*958 grains car- 

 bonic acid and 0*346 grains water. 



I. 5*697 grains substance, air-dry, gave 9-706 grains iodide 

 of silver. 



II. 3*611 grains substance, air-dry, gave 6*140 grains iodide 

 of silver. 



No. 1. 

 Carbon .... 3*48 

 Hydrogen ... 



Oxygen 



Iodine 



100*000 100*000 100000 

 Calculation. 



100000 100-000 1104*8 



The formula is therefore C^ H^ I^ 0^. 



The decomposition by which iodomecone is produced from 



